My own data points:
1) CO app has banner, as stated above that app will no longer be supported on 3/1, however I also get an error when trying to log in telling me to use the UA app.
2) I recently booked an award itinerary using CO miles and my OnePass account number for travel in March (since the M+ number will actually be the OP number, and the surviving system Shares will already have the record, although the flight is operated by UA). That reservation no longer appears online when I log onto co.com or the app. I was able to find it with the PNR, and verified the OP number is in there, but I can't get it to display unless I search for it.
3) I recently sponsored an upgrade for someone and it didn't clear. The RPU was returned to my bank on co.com and on 1/1/12 it simply disappeared. A call to the Plat desk was less than perfect, though after saying "the integration team pushed it from my M+ account" he stopped challenging me, got integration team on the phone and they put the RPU back in my bank, with little further hassle.

Say what you will about .bomb, but all these "glitches" on the co side are making me very careful to PRINT OUT EVERYTHING going forward until I have a sense of stability from the platform post integration.