The worse part about that is with IE9 pretty much begin phased in as the new standard for everyone that's running anything newer than XP (_a lot_ of users) we're finally at a point where we can improve the attachment system without having to rely on flash (which is also begin phased out).
With IE9, Firefox, and Chrome all supporting more and more of the latest web specifications every day we should be seeing GUIs that behave more and more like desktop applications. To see basic things not working at this early stage is worrying. Attachments shouldn't just be working, if you have a recent webbrowser the actual interface should be much improved over what everything (including xf) has been using for the better part of 15 years.
This is the first time IB has developed a version of vBulletin from the ground up. They've gotten a lot of things wrong in the CSS/HTML/javascript departments, the amount of SQL queries per page is worrying, and from what I've been told the php isn't much to look at either. But I'm withholding full judgement until I see for myself.
I'm hoping this is just all kinks to be worked out and people are making a mole hill into a mountain but I'm also worried because if the basics are sloppy when they start tacking stuff on top it'll just get worse. Now is the time to get rid of the tangled mess of code that is vBulletin 4 and start anew, making yet another tangled mess just defeats the entire purpose of having a clean slate. I'd rather them take 1 more year to really work on this before pushing the first RC than rushing what they've shown out to market.