Sprint announced its first LTE phones at CES, but can't muster much enthusiasm for Microsoft's smartphone platform.

LAS VEGAS – Sprint is making a big jump over to LTE. The company won't be introducing any more WiMAX smartphones, Sprint's VP of product realization David Owens said today, preferring instead to bulk up its upcoming LTE lineup. And those LTE phones will be Android phones, at least for now, as Owens had some tough things to say about Microsoft's Windows Phone OS.

Sprint launched its first two LTE smartphones here at CES, the flashy Samsung Galaxy Nexus (we have a full review of the ) and the , which we did a hands-on with earlier at the show.

With those two in the pipeline and more phones potentially coming "by midyear" when Sprint launches LTE, the company is pretty much done with launching WiMAX smartphones, Owens said.

"We've just gone through an extensive set of launches," which will keep Sprint's product line fresh for a while, Owens said.

"April, May, June, July, August, those will be very aggressive times for us," Owens said.

And he warned that Sprint will probably over-deliver on its LTE buildout promises. While Sprint has only promised four LTE cities by the middle of the year, "By the second half of the year" means "between now and midyear," Owens said. "Other markets may launch in 2012," too.

Owens couldn't guarantee that LTE data plans will be truly unlimited, though. He was being coy; he said the Galaxy Nexus "is tailored for an unlimited plan" and told me to "think about where we sit today," but when asked flat-out, held the line that "we haven't announced pricing and service plans yet."

While the Viper and Galaxy Nexus will come out first on other carriers (MetroPCS and Verizon respectively), Owens said they won't look old when they arrive on Sprint.

With the Galaxy Nexus, Sprint is bringing exclusive features, he said. Sprint's Galaxy Nexus will feature Google's very heavily promoted Google Wallet mobile payments service, which is missing from Verizon's model, as well as much better Google Voice integration.

With the Viper, Sprint is betting on having a faster and more complete nationwide network than MetroPCS offers on its similar LG Connect 4G.

Windows Phone Isn't Doing Well

Sprint is looking at giving Windows Phone another stab in the "August-September time period," Owens said, but he couldn't muster much enthusiasm for the platform.

"We have a Windows device in our lineup, but honestly, it hasn't done well enough for us to jump back into the fire. We told Microsoft: You guys have to go build the enthusiasm for the product. We'll train our reps on why it's great...[but] the number-one reason the product was returned was the user experience," he said.

"We want to participate in the market, but we can't build that brand by ourself," Sprint director of product development Lois Fagan pitched in. "We're cautiously optimistic, but [Windows Phone] just hasn't taken off."

Google's Android OS and Apple's iOS may have the market locked down, Owens mused.

"There's a tremendous market momentum that Apple has...and I think Ice Cream Sandwich, and what Android's doing, will continue to have momentum. It squeezes down to such a small subset what's left," he said.

Sprint also carries RIM's BlackBerry phones, but sales of those are in decline.