I will discuss it with my gaming group.
I will probably by the books, how quickly will depend on reviews posted here.
2 players will by the new books as soon as they are avalible, 2 will not, the last im not sure about. I won't change over the existing game - but the PCs are 8th level already and my games tend to end around 12th.
When 3.5 came out we continued playing 3.0 for a while (although using the new ranger for NPCs) then swiched DMs and the new guy ran a short 3.5 game. When I started again, it was a hybrid, in the same world, but on a different continent. My last enthusiastic change was to the XPH - when it came out 3.0 psionics was discarded quickly and totaly (except for the soulblades continued as a prestige class, although it was never actually used.)
I once made a list of how often the editions had changed, counting skills and powers as 2.5ed