Update at 1:30 p.m. ET: RIM has updated its statement and clarifies its position on the next-generation enterprise offiering. In a nutshell, we got it wrong. See: "RIM: BlackBerry Enterprise Server will support all devices; We goofed".

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RIM is developing a new version of its BlackBerry Enterprise Server (BES) for BlackBerry 10 devices because the existing offering is incompatible with the next-generation platform.

According to a BGR report, it's why the Ontario, Canada-based firm's failed to include email and BlackBerry Messenger support at the launch of the BlackBerry PlayBook device -- because the QNX-based operating system couldn't communicate with RIM's existing server infrastructure.

According to the report, RIM will cease development on the current BES server, version 5.0.3, but will issue security patches for "well into the future," according to a RIM spokesperson. BES server version 5.0.4 will be compatible with BlackBerry 10 devices only.

The kicker? If you're running Java-based devices -- such as BlackBerry 7 devices or older -- and BlackBerry 10 devices that run the new QNX-based platform, your enterprise network will have to retain a legacy BES 5.0.3 server as well as a newer BES 5.0.4 server.

It's a move that could increase infrastructure costs in the long run because older BlackBerry versions will have to remain on the legacy BES server while newer devices will have to be hooked up to the newer BES version.

The new BlackBerry 10-compatible BES server, codenamed "NG" for 'next-generation,' will integrate Mobile Fusion and support for the BlackBerry PlayBook.

RIM currently has 78 million customers in total around the world that use the consumer driven BlackBerry Internet Service (BIS). Governments, businesses and enterprises -- a smaller proportion -- continue to use BES for secure communication and messaging, contacts and calendar synchronization, and other business uses.

A RIM spokesperson told ZDNet in an emailed statement that it "does not normally comment on rumor or speculation". However:

As we announced at BlackBerry World, BlackBerry Enterprise Server 5.0.4 will be available later this year and we will continue to maintain BlackBerry Enterprise Server well into the future. Research In Motion is a leader in enterprise mobile solutions and we are committed to continuing to innovate solutions that fulfill our customers’ requirements.

So, no answers there, then.