One thing about the new bidding system is the amount of clients who post jobs simply to get free advice or samples, chat about their work, or try get freelancers to work for unfairly low amounts. outside odesk, or under conditions not mentioned in the original job posting.
The problem is that, unless you apply in the first place, you don't know if they're legitimate or not. Currently, if I get a sense that they're not, I withdraw my application. However, with only 2 applications now available a day, I will have to be very careful, as many will otherwise simply be wasted on oddballs, timewasters and frauds.
Banning free samples completely might be a good first step, as would limiting the amount of interviews the clients are allowed - Odesk's new policies are entirely geared to the convenience of clients. I'm not completely against what they're trying to do, but merely removing 10,000s of small freelancers from develping countries is not going to magically improve the quality of some of the people posting jobs here.
One of the best clients I've got had 2.3 rating. I went for the job anyway, and he turned out to be brilliant. Now it will just be the same 20+ editors going for the same jobs all the time, and loads of people will not have access to any decent proofreaders/editors at all because nobody will want to waste their precious bids.