First, I'm glad to see him racing on the track again. I was (and still am) a strong supporter of his decision to move to the marathon when he did. However, I have been less supportive of the decision to run only the marathon in the last several years and having such limited racing schedule. I still think the kid could scare 27:00, if not break it, if he'd ever focus on the 10,000 for a while. But I'll take a 5,000. Seems to me they said they were going to work on his 5,000 fitness before gearing up for Chicago, so this is probably a test of fitness at the end of that stage.
Second, a prediction? I won't be surprised by anything between 12:55 and 13:45 because (1) it's been so long since he's raced down in this range, (2) historically he hasn't put up great performances during marathon prep but this one seems to be a little different than what they've done in the past, (3) don't know how seriously they're targeting this or whether it's just a test along the way. 12:55 won't surprise me because this is the same kid who ran 13:16 five years ago and has only gotten stronger since then, laying down 59:43 and very solid marathons (2:06 in London, 2:08 in Boston). 13:45 wouldn't surprise me if this is just a fitness test during marathon training, he hasn't raced seriously on the track in years and he may not be really prepared to run a fast 5,000.
Either way, I'm glad to see him doing it and I'll be eager to see the results.