Whoa there, RIM — not so fast. Despite an earlier commitment from Sprint, the Wall Street Journal reports that the Now Network has cancelled its plans to bring WiMAX to the BlackBerry PlayBook, leaving Research in Motion to continue selling WiFi-only models of the half-baked tablet. Sprint representatives cited poor adoption rates among business customers as one reason for the move to cancel PlayBook sales, along with an already crowded tablet market, also adding that the decision will have “no impact” on the carrier’s relationship with RIM. We can’t say that a WiMAX-capable PlayBook would have topped our back to school wish list, but this latest move is somewhat shocking nonetheless.

Update: RIM wrote in to share the following statement:

RIM has decided to prioritize and focus its 4G development resources on LTE. We remain excited and committed to delivering innovative and powerful 4G tablets to the US market together with our carrier partners. Testing of BlackBerry 4G PlayBook models is already underway and we plan to enter labs for network certifications in the US and other international markets this fall.

Will RIM’s PlayBook get WiMAX? The Now Network says no (update: RIM focusing on LTE) originally appeared on Engadget on Fri, 12 Aug 2011 15:21:00 EST.