We've gotten reports as well as TUAW that there will be an Apple event tentatively scheduled for February 26th. The event will likely be the launch pad for the iPhone/iPod touch SDK and applications including Exchange support and Lotus Notes support.
It could also be the launch pad for the new MacBook Pros which have been waiting for the late to the party Penryn chips. Since 10.5.2 builds have been lingering around for awhile now, it might also might also hit around then. Did we forget anything?