At the moment, the assets are pretty hard to value, though. If, for example, I have 1 CRAPCOIN UIA in my wallet and the issuer has chosen to list it for sale on the exchange for 1,000,000 BTS/CRAP (and there's no functional market for crapcoins), then on the top right corner of the interface, it shows my wallet having an estimated BTS balance of 1,000,000 higher than it should be. I don't know how else you would value those, though you could tweak the measure a bit.