I'm in design school after almost 20 years of designing as a hobby, and just bought a new copy of CS6 since I had been using CS4. Here's the problems I see with the Creative Cloud.
1) It will be easier for pirates to get copies to pirate.($50 for a month and hack it vs. thousands for a version to hack) Piracy will become more prevalent.
2) Creative Cloud may be cheaper when you look at Adobe's release schedule now, but what happens years down the road. Maybe it's 2 years between updates now and the math works in Creative Cloud's favor. Years from now, it moves to 3 between updates... then 4... and before you know it they aren't updating it anymore because they already have everyone locked in. They get your money either way so why spend for more research and development. You are now paying $600 a year for a program that hasn't been updated in years. (if they don't raise the price after everyone is forced on board)
This will be good for the guys/gals that only need the programs for a few months, but as for the ones that need it long term, they are getting shafted. This only stands to hurt those that legitimately buy the program, use it and upgrade regularly. It will encourage piracy, and hurt the hardworking consumer. I think it's a bad business move.
I'm not saying Adobe is a bad company or that they would actually do these things, but the potential is there and this is a huge step in that direction. Someone needs to build up a company to compete with Adobe. As much as I love using their software they do have a sort of monopoly in that market.