I sort of touched on moving Callaspo to DH here and Clark Fosler brings it up here, along with Callaspo's defensive shortcomings. There are bigger problems with this team than Callaspo playing second base and actually a Kila/Guillen platoon at DH would be ideal. But I think DM/Trey still view Guillen as an everyday right fielder and Kila as a career minor leaguer - despite evidence to the contrary.
Normally you wouldn't think moving a middle infielder to DH would upgrade what's supposed to be a power bat but KC designated hitters hit .209/.281/.374 in 2009 and .268/.309/.446 in 2008. The last two years Callaspo has hit a combined .302/.358/.433 for a 111 OPS+. He would clearly be an updrade.
Now if Aviles comes back 100% then it makes the defense better and though he probably isn't the hitter he was in 2008 I think he probably is just a notch below. If he can't come back then Bloomquist would play second and though he has a weak bat we all know he is going to continue to get a lot of playing time so KC may as well take advantage of his defense.
The more I think about it the more I like it. And if it's not Callaspo then I sincerely hope it is not Jacobs.