One of the things I did last week was migrate my feeds to Google from FeedBurner. For the most part things went smoothly, although subscriber stats are still low. Ironically it appears that all of the Google Reader subscriber numbers have been missing since the move. FeedBurner would often drop those numbers so it was not surprising that they are still having problems with them now that I have my feeds at Google.
One of the things I was not expecting switching my feeds over to Google was a 502 error. Thankfully it only appears to have lasted for a day, but I have read that some people are having more issues with the 502 error. If you have migrated your FeedBurner feeds to Google you might want to subscribe to the new The FeedBurner Status Blog. You can get recent information on the status of FeedBurner, including a work around to try if you are getting the 502 error.