I did this last year, and here's how it worked:
I paid for the conference on a corporate credit card well in advance of the conference, so I didn't want to deal with reimbursing my company for a party pass for my wife. I emailed someone at VMWare, and they told me the passes were available at check-in. When I got to Moscone to check in, they had a separate line for folks who weren't pre-registered. I went the day before the conference started, so the line was minimal. I paid for a guest pass for my wife using a personal credit card, and this entitled her to attend the Welcome Reception in the Solutions Exchange, as well as the party.
She had a great time at both, and not being a techie, it was good for her to see a little bit about what I do for a living (at the Solutions Exchange) and she enjoyed the party quite a bit. $275 seems pretty expensive, but keeping my wife happy is priceless. 
Information about the entertainment usually leaks a week or two before the event. I'm not sure why VMWare says "More information coming soon" when in reality they never released anything or updated that page. But the party last year was great (albeit a bit crowded in the old hangar), and I'd suspect this one will be great too.
Hope this helps!
-Kirk
posibably Barry Manifold or REO Speedwagon
Tom Howarth
VMware Communities User Moderator
Am I the only one that gets this one? LOL
