You already trust 8 other nodes that they are sending you the proper block chain, what would be the difference in changing that to trusting 8 nodes that they are handing you your proper account balance and information?  And if you didn't want to rely on that, you could always continue storing the blockchain on your own computer.  It'll get large, sure, but that's the price you pay if you don't want to trust other nodes.

I think the biggest issue to figure out is how the nodes that keep the block chain will be paid for keeping the block chain and answering queries about it.  Obviously, pools have their fees, and will have to maintain the blockchain in order to hand out work to pool miners, but they could potentially just refuse a lite client's request to get information about a given list of addresses.  After all, if most people are reliant upon a few dozen nodes total, then there could be a LOT of data transfer and computational power needed to answer as many requests/second as would inevitably be generated.