The new and highly anticipated revision of the MacBook Pro is rumored to be released on March 1st, 201, according to the latest speculation from blogger KennethLund.dk (via MacRumors. As pointed out in the report, however, there tends to be a fair amount of speculation when revisions to new Apple products are due to appear so this date could be erroneous. The evidence for the March 1st date comes from Danish Apple resellers who are expecting shipments of the new MacBook Pros on March 1st.
While the MacBook Pro last received a significant refresh in April 2010, it is not clear yet if Apple will be going in a new direction with its professional level laptop and releasing a new design rather than a spec bump. We have noted that the new MacBook Pro will likely forgo hard drives in favor of the solid state drives (SSD) as seen on the new MacBook Air. While this would likely result in a cost increase in the higher end models given the cost of 512GB solid state storage, there are other tactics that Apple could use in order to maintain professional level storage and functionality.
Some have speculated that the MacBook Pro would be similar to the MacBook Air in that the optical drive would be removed to save on weight and space and perhaps to allow dual hard drive / SSD storage. Apple certainly has no qualms about removing optical drives given the cost and size of flash memory stick storage and it certainly does seem the most appropriate thing to do (especially given that those who desperately want a DVD drive can always use an external device).
In addition to the major design and storage changes we have speculated on, expect the usual jump in processor power and speed, with the new models likely utilizing the latest Sandy Bridge microarchitecture from Intel.