I don't think Vander Plaats said anything about the candidate attending this announcement. But just for fun, I checked the Tuesday travel schedules for the remaining 4 candidates in the running:
Newt Gingrich: Has 10am event in Mt. Pleasant. Couldn't make a 10:30 in Urbandale. Nearly 145 miles away. Too far.
Michele Bachmann: Has 11am in Fayette. Couldn't make it there in time, even in her giant bus, if she's in Urbandale at 10:30. Nearly 250 miles away.
Rick Santorum: Hmmm, this looks interesting. 9am stop in Pella. 12:30 in Mt. Pleasant. But when you start to do the math, the math gets tough. If he kept his Pella event to just half an hour, he could make the hour trip to Urbandale in time for the 10:30 start. But it wouldn't be possible to do the Vander Plaats event and then drive to Mt. Pleasant in time for the 12:30 scheduled start. That trip takes nearly 2 1/2 hours.
Rick Perry: He's our last chance here. Perry has no public schedule released so far for anything in the morning before 11:45 event in Maquoketa. Hmmm. So he could do a 10:30 in Urbandale and then go on with his day. However, the distance between the two cities is about 180 miles. That's pushing 3 hours of driving. Unless, he flies, of course. Then, it might be doable. And in case you wondered, he spent Monday in New Hampshire.
So I'm going with Perry. But it's only a guess. And that's only if the candidate actually appears with Vander Plaats at the announcement.
Guess we'll know soon.