Fred, I think you've hit on something that I've been thinking about for awhile and I've seen very little discussion about. I think the short stack of resources given to the young, rookie GM is indicative of the risk the upper management recognizes going into the season. They can't get hit with a bunch of injuries, and even if they don't, some very large question marks need to come up positive for this team to have the look of an October contender. The contingency is thin. With that being the case, I think any mid-season spending is absolutely dependent upon good early results. A poor April/May, and I think upper management packs it in for the year with sights set on 2013. If things go their way, I'm confident they'll be active addressing what they need for the stretch run and playoffs.
Also, remember, there is some built-in roster supplementation for the 2nd half as of right now. Matsuzaka, Hill, and Bailey will be there to bolster the pitching down the stretch.