I don't think wells is insolvent so much as ahead of the curve. This was probably some sort of position taking as they watch those around them suffer.
If you look at the 3 biggest retail bank failures so far: wachovia, wamu, and indymac, all three had portfolios that differ significantly from wells. Yes, wells had extensive alt-a and even sub-prime (can't attest to that being extensive, because I didn't use them), but no where near the level of option arms and other aggressive arms products.
Plus, I'm not sure of the numbers, but I'm under the assumption that they are not even in the same league as those who failed in terms of market cap, or depository accounts. In other words, my thought here is not that they're too big to fail because they're integral to the financial system, but more like they're too big to fail... Period.
I'm sitting next to Quinones in D.C. right now who is pulling up their 10q right now to confirm.
He should be responding soon with his findings.