In reply to Tomas M..

Post formats are 'just' a custom taxonomy, so the only change would be how they're declared in your function.php (or wherever) file. That would also mean you could define your own formats (such as 'tweet') that you can't do with the baked-in version. All the alls in archive.php, single.php etc would stay the same. Some sort of conversion process / code would be helpful though.