It depends. If you get a file manager from the Play Store (I use a free one called File Manager) you can move your media files around, however you will still have the 2GB / 11GB split.
More recent versions of android treat all internal space the same so it can be used for apps or files. Earlier versions didn't: they kept 'app space' (the 2GB partition) separate from 'internal storage' (the 11GB partition).
The S2 came out around when that was the case. Since merging the spaces would have meant people losing all their data, I don't think regular upgrades changed this, so even S2s running a more recent version of Android still have the old style split.
I would imagine that if you root the phone, you could fix this (though you would need to backup as it will wipe your phone). For more information, check out the Rooting section of the S2 sub-forum on here.
