if so how do i download it

Yes, it is.

do you download it at ncsoft? cuz i got an error at 98%

That error's been around for ages. Uninstall your Ncsoft downloader, reinstall, then install Aion if it is doing that.

I thought it doesn't go free to play for a few days yet, or has that been changed?

EU server-free for awhile
NA server- free on the 11th (ppl play the trial to keep playing, all ppl with the trial get to KEEP their accounts and toons)

Trial only goes til lvl 11
This goes way past the trial. It's f2p now. Just can't join the new server or use any of the character transfers. Also, if you have an old account,
you may now log onto that old account and continue where you left off.
My account has been inactive since early 2010 and I still have all my characters

A "Starter" account isnt worth shit tho.

It's apparently free to play now. Just downloaded it. Gonna try it. I've been looking for a decent MMO to play for free.

I've had it for about a week now, it was f2p before yesterday.