US transit planners have a poor record with integrated transit planning, and designing accessible stations. So will California HSR learn from those past mistakes? It seems unlikely, to judge from a recent workshop moderated by Jeff Morales of the CHSRA.
I note in particular the presentation by Stan Feinsod (of the “National High-Speed Rail Connectivity Center”). His talk on station access not once mentioned bikes or pedestrians. And it is curious that the panel included an aviation security expert (though thankfully he didn’t go full TSA).
On a positive note, Armin Kick of Siemens gave a good talk on interoperability (skip to the 29 minute mark in the video). By using real-world examples from German HSR lines, he shows how regional and commuter services can exploit the new HSR infrastructure. To do that, they all must use the same platform height, and the same signalling standard (hint: not CBOSS).
Systemic Failure 
The California High Speed Rail Urban Design Guidelines talk a whole bunch about bicycles and pedestrians— http://www.cahighspeedrail.ca.gov/urban_design_guidelines.aspx They even talk about bike stations!
Of course, that’s a rather old document, but one take-away point is that planning for pedestrian access will be largely left up to the individual communities where stations will be located. See, for example, the Anaheim Regional Transportation Intermodal Center—http://www.articinfo.com/ —which is intended to get people from the CAHSR to local destinations and back without needing a car. This in Orange County, of all places.