The DH and I found that the bus service to WL was pretty good. Downtown Disney and Typhoon Lagoon are about the same amount of time since they are pretty close together. Blizzard Beach will take longer since it's more over by Epcot.
I would say at least 30 minutes to DD & TL. I can tell you that we had to wait a bit for a bus to come back and pick us up at TL for quite a bit, so make sure you build in time there. 40 minutes would be a safe bet.
1986, 1995 - Off Property
1995 - B.V. Palace
2002 - PORS
2005 - Wilderness Lodge
2006 - CBR
2007 - AKL
2008 - Saratoga Springs
Spring 2009 - BCV
Fall 2009 - CSR
Winter 2009 - VWL
Spring 2010 - BWV
Fall 2010 - Kidani & Wine & Dine 1/2 Marathon
December 2010 - OKW
I found our average bus travel time to be about 35 minutes from the WL to virtually everywhere on property.
The bus stopped frequently to pick up guests at Ft. Wilderness as well as the Polynesian before proceeding to the parks. The actual travel time hovered around 20 minutes and the average time we waited for a bus from the hotel was 5 min. Sometimes, we waited up to 15 min at the parks before a WL bus pulled up.
We were there during a very slow time of year (early Feb) and I think that if you will be visiting during a more busy time, there will be more frequent buses and potentially LESS sharing buses with other resorts.
A good rule of thumb is to leave your room 45 minutes before you want to be at the front gate of the park of your choice.
Natalie INTERCOT Staff: Disneyland Resort-California, The Water Cooler