Hi John,
Currently we support desktop browsers for voice, video, im and presence related capabilities. Our goal is to always support the latest desktop browser versions of Chrome, Firefox, IE and Safari. However, sometimes formal support may lag the release of the browser.
Mobile browser support is on the roadmap for IM & Presence but I don't have a release date for this.
Unfortuntately, because mobile browsers don't support plugins we don't have a plan for cwic and the plugin to work on mobile platforms at this time. 
Note that you can launch an installed Jabber client from within a mobile browser: http://developer.cisco.com/web/jabber-developer/the-jabber-application to make a call or start an IM. 
Mags