The web site claims it's possible. It lies, the link first forces a new registration and then takes you to the usual download link.
Here's the inaccurate/misleading page on the RoM site:
http://us.runesofmagic.com/us/free-mmo/register.html
as well as getting my hopes up about getting my "fix" while waiting for this interminable download, I've also misled at least one person who wanted to try whatever game I'm playing.
What's with gaming companies doing this? I've been hunting for a browser game to play while I wait for this download (or replace RoM with entirely, if I get hooked while waiting) and I've found at least one other game with a "play in browser" link that leads to a download page; perhaps it's from the same company.
In any case, RoM, this is not a class act. Fix your web site.