Shouldn't have any issues. In any case, I'd change the TTL to something short (say 5 minutes), wait till the current TTL expires (if the TTL was 1 day, wait a day) and then make the move. This way, you'd be able to quickly recover from any potential issues during the migration with a very low downtime.
Once the migration is complete, verify things work (DNS queries from multiple locations, etc.) or wait a few days to hear of any issues. You can then reset the TTL to something larger.