Joe Mauer and first base

Ah yes, Joe Mauer bunting. Among my least favorite scenes ever at a Twins game. Last night he played first base, something that I wasn't too fond of either.
Let me get one thing straight. He was excellent at first base last night. That's part of the problem. Now, the team will be more willing to put him at first regularly. What does this mean for Justin Morneau? In essence, if you want to move Morneau you are saying you are OK with replacing Morneau with Drew Butera in the lineup. I am not OK with that.
Joe Mauer adds value as a catcher, because it's not a position in which one expects to see a lot of offense. A low power corner infielder is significantly less worthwhile, despite his batting average. That said, with the emphasis on defense that the Twins have, I worry that the team might think that it would be totally OK moving Mauer to first for good, not thinking anything of the marked lack in production the line up would have.
Of course, maybe playing first will spare his legs a little bit, and his lower body strength will allow him to start hitting it out of the park? That's the only good resultant scenario, I think.