Personally, this year I was interested in the 70-200mm f/2.8 IS USM II. I was also considering getting the classic (but old, may be on its last legs for resolution) 400mm f/5.6 non-IS, along with perhaps another $1000 lens (can't remember what at this point). Right now I'm looking at the new 70-300mm L, which does have a "modest" (Canon's phrase) maximum aperture (especially at 300mm) but looks to have incredible IQ at all points of the range. If it's around $1500 that also helps the sticker shock substantially (enough that I could replace my T1i with the extra $1000 saved), and the extra 100mm over the 70-200 is very important to me. I'd gladly pay an extra $1000 for a better maximum aperture but you can't have everything.
So for a while I think that will more or less be the last word in 70-300mm on the Canon platform, unless they release one with a better maximum aperture (I'd gladly pay an extra $1000 for an improvement in that though).
I don't care so much about the 50mm f/1.2; the original seems not to be as sharp at normal apertures as the f/1.4, which in turn is claimed not to be as sharp as the compact macro (Ken Rockwell sez...take it with your shovels of salt, I guess, but I assume he's right; MTF curves on Canon's website seem to confirm that at f/8 the 1.4 is sharper towards the edge of the frame, though the 1.2 seems to have a slight boost in the middle). The f/1.2 is expensive. I'd consider getting one all the same, but I shoot with the 50mm at "reasonable" apertures more often so sharpness at those apertures is very important.
Plus the f/1.2 was released in 2006. Those pro lenses don't seem to be upgraded as quickly as the cheapies, probably because Canon wouldn't remake them for cost savings as you can see happened to the original 50mm 1.8 (which looks like the f/1.4 build-wise) to the II. How realistic is it to get an upgrade already?
It's the f/1.4 that is crying for an upgrade, and which I voted for before when this was on the front page of CR.
DO lenses...I wonder if this wasn't a failed experiment on Canon's part. The 70-300mm has weird defocus characteristics (doughnut boke). Again, these are also pretty new lenses, but apparently the 70-300mm is not so well loved so Canon probably isn't rushing out with another. These may eventually catch on but they ought to solve the defocus characteristics issue first. It's a shame because that lens reportedly doesn't change focal length when zooming - no focus breathing - which would be perfect for video.