I stopped by the new Costco last night after work. It seems they've been open for about a month but apparently close pretty early on weekends, which is why they weren't open the time i walked by before. The parking wasn't bad at all for a Costco, especially a Costco at a mall. Nor were the lines inside at the register that bad. I suspect perhaps the fact that it's open now just hasn't percolated to a lot of people yet (say, like me as of last week) so the crowding situation might definitely get worse. Other than that, it's got a pretty standard Costco layout, with just enough sections switched around to really confuse you if you're used to shopping at another one. I ended up spending about $130, $20 of it on rechargeable batteries, the rest on food and snacks and drinks, mostly for this weekend.
I'm torn about leaving for BayCon this afternoon vs leaving very early tomorrow morning. Leaving today would probably get me an extra 4-6 hours of con and an extra 6-8 hours of sleeping in the car. I may try to call up the hotel soon and see if they've got any rooms available for saturday night. I'm sure they've been solidly booked for awhile, but they always have cancellations at the last minute, and if you manage to ask at just the right time you can snag the free rooms.
If i can get a guarantee that i'll have access to a real bed and my own shower for one night, rather than sleeping in my car and having to beg borrow or steal shower access from somebody (probably the gopher suite) then it would make heading up today a lot more attractive.