I find myself clicking a lot when it comes to switching forums (channels) and very often I simply click on "Forums" in the header navigation bar and start from there again in order to reach a certain forum (channel). This makes me thinking about how navigating in vB5 could be both more comfortable and more fun. In vB4 we have some sort of "quick navigation" on the bottom of every page, however I find clicking there is even an unneccessary click.
Suggestion:
Why not use the breadcrumbs in vB5 to generate a "quick navigation" on mouseover? I tried to demonstrate it in the attached screenshot. Although I am not that good on doing mockups, I think you get the idea: Whenever the user moves the mouse over the breadcrumb, the corresponding sub-forums (channels) appear, maybe with a short delay of 300ms or so. This should work on all parts of the breadcrumb, except the currently selected topic of course. As a result one could easily navigate through any sub-forums (channels) and even clicking is only required once (which is selecting the new forum/channel), as the "quick navigation" shows up on mouseover.
Screenshot:

This issue is also in JIRA: http://tracker.vbulletin.com/browse/VBV-10551
Suggestion:
Why not use the breadcrumbs in vB5 to generate a "quick navigation" on mouseover? I tried to demonstrate it in the attached screenshot. Although I am not that good on doing mockups, I think you get the idea: Whenever the user moves the mouse over the breadcrumb, the corresponding sub-forums (channels) appear, maybe with a short delay of 300ms or so. This should work on all parts of the breadcrumb, except the currently selected topic of course. As a result one could easily navigate through any sub-forums (channels) and even clicking is only required once (which is selecting the new forum/channel), as the "quick navigation" shows up on mouseover.
Screenshot:
This issue is also in JIRA: http://tracker.vbulletin.com/browse/VBV-10551