I have migrated to wp.com successfully from blogspot.com, I had posted earlier that there were some hiccups but once the bugs got fixed at wp.com , things were very easy. I am not sure if this importing to wp.com is documented but just in case if someone finds this useful here are the simple steps.
1. Take a back up of your blogger template.
2. Go to the url http://.wordpress.com/wp-admin/import.php
3. Select the type of hosting of your previous blog – for me blogger.
4. Log into your blogger account in this page .
5. Select your blog
Now sit back and relax ( it would take couple of minutes )