G20 Leaders Summit in London - What to expect?

In my opinion, the expectation is that we won't be able to expect much from it anyway. Other than the usual photo ops, and some promise to overhaul the financial regulatory system, please don't be too hopeful.
Instead, expect rifts to surface, and BRIC countries demanding their rights in IMF, and China drumming for a new world reserve currency. US and UK are demanding every country to increase their stimulus bill, while EU is fighting for financial regulation. It will be a miracle if any significant achievement could be attained in this summit. At worst, nothing will be achieved, and protectionism sets in. That would be global trade's worst nightmare.
My 2 cents: We will need another summit soon after this to stabilize the global carnage that would likely ensue after this. Bloomberg has an article on this subject as well, written by Matthew Lynn.

http://www.bloomberg.com/apps/news?pid=20601039&sid=aofSy5x6fwYY&refer=home