Many sources report that Apple is questioning the future of its Mac Pro line. It is difficult to say if the Mac Pros time has come to an end but sales are dropping and customers prefer new Apple's laptops. The delay in the delivery of Xeon Sandy Bridge processors might also play a role. The prices are also high if you compare them to the competition.

Apple Insider has more information on this matter. The website does not reveal its sources but it seems that the information comes from inside Apple:

"Although the Mac maker has reportedly developed a revision to the existing Mac Pro that may or may not see the light of day, people familiar with the matter said management as far back as May of 2011 were in limbo over whether to pour any additional resources into the product line.

According to these people, the consensus among sales executives for the Cupertino-based company was that the Mac Pro's days -- at least in its current form -- were inevitably numbered. In particular, internal discussions were said to focus around the fact that sales of the high-end workstations to both consumers and enterprises have dropped off so considerably that the Mac Pro is no longer a particularly profitable operation for Apple."

Notebook sales represent now 74% of whole Apple's computer sales and the high-speed Thunderbolt technology should allow the company to create products that could easily replace the Mac Pro line.

Source: http://www.appleinsider.com | http://www.macrumors.com