The Pirates should go after Rockstar for illegally distributing there Intellectual Property. yes, I know it wouldn't work, but it'd be hilarious, and serve them right.
last I checked some patches for the dealloc empty file problem was being merged in 2.6.30. if you want to avoid it but want some other advantages like faster fscks you could go with data=journal on your filesystems which is a bit slower but also disables dealloc, while still having extents, barriers, and other ext4 benefits. I've been using data=journal on my
it also depends a lot on what you have in 'production'. a web server that's mostly doing reads it should be fine for. a heavy email server... well.. can you afford to lose email on a crash? I think it might be alright for a server that just does mta but not the fs for the actual mailbox's (with dealloc anyways). database server should be fine, because the database's job is to make sure data hits the disk, among other things. dns servers are a very read heavy so again I would think it'd be fine. so basically you need to watch anything that's heavy write and not to a database, and even then only with dealloc.
still as I'm sure others have said, it's a good idea to wait on new tech like this. some tools don't yet recognize that ext4 is not ext3.
You will lose an important tape file.