I'm still using mostly 1Gb cards, CF and MS. A typical day's shooting for me will be 2Gb, may be 3. I then transfer on to laptop, and wipe the cards. Perhaps not the most risk free option
I am hanging off buying more cards until I see what the next batch of Sony dslrs use. I am guessing SD and MS. (I am about to buy a Sony DSC T500 as an alternative to a Flip Ultra HD etc. and so will probbaly get a 4gb MS to go with this.)
Nex 5, Nex 6 (IR), A7M2, A99 and a bunch of lenses.