I haven't read this thread much at all, so maybe this has already been said, but I've been noticing a lot of people saying things like, "If the block size isn't raised, then that would be bad because ..." But just wanting larger blocks isn't a good argument for increasing the max block size. By far the most important issue is what the network can support. We're just going to have to learn to deal with the fact that the network's capacity is limited and fees will probably always be larger than many people want.

Exactly what block size the network can support is very much debatable. I currently think that 10 MB would be fine and 50 MB would be too much, though these are mostly just feelings. There should be more rigorous study of the actual limits of the network. (Gavin's done some nice work on the software/hardware front, though I'm still worried about the capabilities of typical Internet connections, and especially how they'll increase over time.)