Actually, it shouldn't be that bad... I live next to Palo Alto, and make that drive quite often, though usually not at rush hour. Dumbarton Bridge is much easier than the other bridges, and I don't think it gets
too crowded. I can get there from University Ave. in about 15 minutes, without heavy traffic. During rush hour I'd guess it'll take around 20-30, depending on exactly where you work.
One tip - get a FasTrak Tag, which allows you to zip through the toll-booth. I finally got one this month, and it's VERY cool!

It automatically adds money from your credit card when your balance drops below $15 - and you're not paying a monthly/set fee, just the same per-crossing charge (recently raised to $4

). If you carpool or drive a hybrid/"green" car, you'll save even more time by driving in the carpool lane... but that's only good for a few miles, and not actually across the bridge.
Here's info on the FastTrak -
http://www.bayareafastrak.org/