Well there was the Mac Pro spring release rumor. If that is going to be a redesign, a keynote for both announcements would be pretty ideal.
I predict 'if' there is any keynote, this March will be about the Mac Pro and new software only.
We know they have been recruiting people in relation to software products over the past year or more and with most of Apples software lineup outdated or in need of desperate maintenance updates - a march announcement of
iWork (not a major update since 09)
Logic Pro 9 (falling well behind Pro Tools once more)
Aperture
Final Cut Pro X (either a .5 update or release XI)
iLife - since they have basically taken two applications away from us iWeb & iDVD apple really need to update iLife and add additional applications to the suite rather than continue down the line of stripping content away.
OS10.9
If we got a March keynote revealing 10.9, new software overhaul of all mac software and backed up by announcement of new redesigned Mac Pro launching a in late Q2 2013, with pre-orders available from after the keynote...you can bet the lack of iDevice announcement will be forgotten.
Apple need to bring some focus 'Back to the Mac'....