Generally the Tip tranny isn't all that problematic - not sure why yours is giving you so much trouble.
As far as the VW dealer taking their time, my guess is that its because they don't really have all that much incentive to move quickly. They're probably charging a discounted rate to the dealer that sold you the car and since they didn't sell you the car directly and don't have contact with you, there isn't much in it for them. I'd start by contacting the VW dealer and trying to form a relationship with them. If the feel like they'll get your service business going forward, they might be more accomodating.
I wouldn't give up on the Passat if your wife likes it (aside from the tranny issues). They're great cars, although a bit quirky and probably not as bulletproof as say a Honda Accord but they do have that something about them that makes them a pleasure to drive.
Hang in there - check out some other forums for good info (and busier activity) like
www.B5ONE.com,
www.passatworld.com and
www.dubberzine.com. All should be good sources of info for you on your Passat.