We already knew a lot about the Wii U based on previous hands-on time with the system and announcements from Nintendo. But now that we have the actual hardware in Opposable Thumbs HQ (read: my Pittsburgh apartment), we've noticed a few things that were a bit surprising. Here’s a quick, picture-filled look at some of those surprises. We’ll have much more Wii U coverage, including an in-depth review of the system and major games, as we get closer to the November 18 North American launch.

There’s a mystery connector at the bottom of the GamePad



In addition to a slot for the charger and a standard headphone jack at the top, the bottom of the tablet GamePad has a mysterious connector at the bottom. The user’s manual says this connector is for "controller accessories," but none have yet been announced. The connector is a thinner than the Wii Remote connector that was used for things like the Nunchuk and Classic Controller. Karaoke launch game We Sing doesn’t use it either—the microphone that comes with that game plugs into the USB slots on the base system. Curious...

UPDATE: Thanks to former Ars writer Ben Kuchera for pointing us towards yet another mystery connector on the back side of the GamePad, as shown above. The female screw hole in the middle of the controller's back ridge is very similar to the kind you'd see on a camera tripod, though the ridge would seem to get in the way of the base for most such tripods. The screw hole, and the divots next to it, line up with the mystery connector at the bottom in such a way that it looks like it could be used to secure a bulky accessory that latches in to both connectors and sits flush with the back of the GamePad. Our best guess at this point: an expanded battery pack to extend that three to five hour battery life...

The GamePad charging cradle uses pop-up contact points

The charging cradle that comes with the Deluxe edition of the Wii U is pretty nice, letting the system slide in easily and securely while standing it up for display. Instead of using a protruding charging point that might wear out as the controller is inserted and removed, the charging cradle uses a couple of small metal contacts that pop up when the GamePad is placed down, touching two small plates on the bottom of the controller. It's a nice touch that allows the controller to slide in and out very easily, and it's a bit reminiscent of the similar charging cradle that came with the 3DS.

The controllers only have digital shoulder buttons



I never really noticed this at preview events, but the four shoulder buttons on the Wii U GamePad and Pro Controller are purely digital. This is a somewhat significant difference from current systems like the Xbox 360 and the PS3, which feature two deeper shoulder buttons that can send variable analog input if they are squeezed more gently, which comes in handy in racing games and other titles that require finer controls aside from the two analog sticks. Ports of these kinds of games on the Wii U are going to have to work around this limitation.

The volume on the GamePad is adjusted by a slider.

This isn't so different from the volume slider on the 3DS, but for some reason I was expecting clickable volume up and down buttons on the Wii U GamePad. Maybe that's because tablets like the iPad have trained me to expect those kinds of buttons. Oh well.

The GamePad sync button is sunk in



You need a pen or paperclip to push the red button that syncs the GamePad to the Wii U system for the first time. It’s a minor annoyance, but not nearly as annoying as removing the battery cover (and sometimes the protective gel sleeve) to hit the similar sync button on old Wii Remotes. On the Wii U Pro Controller, the sync button sticks out so you can press it with your finger, which is kind of an odd difference.

The system is really deep



The Wii U’s physical dimensions have been well known for a while, so at some level I knew that the system was quite a bit deeper than the first Wii. But looking at the systems next to each other (as in the top view above), it’s quite striking just how much farther back the new system (black, left) juts into your entertainment unit. Looking back, Nintendo has done a good job of hiding this depth at pre-release events, often keeping the system in a cabinet that only showed the hardware from directly head-on. The Wii U is also slightly taller and wider than the Wii, but those differences are not nearly so pronounced.

The text on the front of the system is aligned horizontally



The way that the text is aligned on the front of the Wii U suggests it’s meant to be set down horizontally, with the long side down. That’s different from the Wii, whose text is only right-side up when the system is standing vertically. Another clue that the Wii U is meant to be laid flat: the system's rounded edges mean it can’t stand up vertically without a set of small attachable feet (as shown above), which aren’t even included with the $299 "Basic" version of the system.

The power brick is kind of big



The same sensor bar and RCA/component cables that work on the Wii will plug in to the Wii U just fine (or you can use an included HDMI cable for a better picture). For the power supply, though, the Wii U comes with a proprietary A/C adapter (right) with a power brick that’s significantly bigger than Nintendo’s old system (left). That’s to generate the 15 W of power that the new system needs, a slight increase from the 12 W needed for the Wii. The power brick size and energy consumption are still nothing compared to even the Xbox 360 Slim, but the increase from the Wii is still noticeable.

The Pro Controller button arrangement doesn't match the Xbox 360's



While we're talking small details, look at the way the various buttons are named on the Xbox 360 controller (bottom) and Wii U Pro Controller (top). That’s gonna be really hard to keep straight when switching between systems. Nintendo has been using this button naming layout since the SNES (and through to the Wii’s Classic Controller), so Microsoft is the one flouting convention here. Then again, if Microsoft had gone with the Nintendo standard, who’s to say the big N wouldn’t sue?

The Wii U Pro Controller lasts 80 hours on a single charge.

This was actually known before the system came out, but seeing this factoid in the user’s manual was just mind-boggling. The ridiculous battery life probably has something to do with the comparatively weak rumble motor in the Pro Controller, so there's a give and take involved here. But the Pro Controller charges by USB in just 4.5 hours, giving a nearly 18:1 ratio between charge time and play time. For context, the touchscreen Wii U GamePad lasts just three to five hours after a 2.5 hour charge time.