There is another reason to not blow up the team in search of starting pitching: the trading chips the Twins do have would not bring the return that some folks here expect. You see comments like "trade Pavano (Liriano, Casilla, Valencia, ...) for a good starting pitching prospect". I don't think offers like that will be on the table, for Terry Ryan to choose from. Capps might bring a second-tier prospect. Span probably could net one legitimate prospect, plus a few pieces to fill out a trade, but even he is probably not viewed as that much above average in CF. Everyone else on the 40-man roster, I think, carries too much baggage of one kind or another, or else is just not viewed as worth very much in the first place. You could back up the truck, and trade every conceivable asset they have, and wind up with only two or three stud starting pitchers for 2013 (or a staff filled with other teams' fifth starters), and then nobody to play behind them.
Most of what the Twins have is more valuable to them on the field than as trade bait. I do expect some trades near the deadline, mainly of the expiring contracts, and look forward to being pleasantly surprised (except for a Span trade) if Terry Ryan brings back anything that looks like a star in the making for 2013-16.