I had the same problem as you this morning. I woke up, got ready for work and chucked the Micro in my pocket. On the bus to work I tried turning it on.... nothing.... dead. I almost had a heart attack. I thought to myself "no worries, maybe the battery is dead" (I hadn't charged the battery in ages). I got to work, "borrowed" a USB cable, plugged it into the Micro and it showed the charging indicator, so I was relieved. I came back later to check on it, but it hadn't been charging! Just the charging icon flashing. So again, I thought my Micro was dead. I took it home, and using the USB cable that came with it, it started charging up properly, but this time it would only go into recovery mode (most likely because the battery was too low for it to go into normal mode). I left it to charge for 4 hours, the battery was full and now it's working perfectly again.
Phew, such a relief! I was worried over nothing