I'll throw another consideration out there - if you'd really like to fly a different route anyhow, then the 49-minute layover at MSP gives you the best chance of a schedule change between now and May 2015 (there will be many) giving you an illegal connection that suddenly provides lots of options without having to worry about specific award level availability. If they move your flights and suddenly have only 20 minutes at MSP, then you may very well be able to get them to put you on a one-stop PDX-JFK-FRA or PDX-AMS-FRA without having to pay anything extra (though the AMS option may be contingent on the award availability since it requires a partner flight).

We've all been giving our opinions on whether we'd prefer the short-ish MSP or DTW connections, but the reality is there will be several schedule adjustments that change your layovers in the next 9 months. That DTW connection might grow to 1hr 15min or shrink to 20 minutes. It's probably not worth overthinking at this point.