as title and my fancy paint picture says:
about - as a place for brief info like build number (date there, instead of titlebar), qt version used, manual update check (?) and so on...
help - containing links, or text with manuals, tips or even faq itself (?)
tabs could be merged if You think its better, or of course contain other missing information. i saw very relevant proposition for files\mb counter - that could also be there. perhaps it would be nice to see some kind of information about program, program creator, link to the main page, forums, perhaps even translators nicks\names ;), info encouraging to submit missing translations and such... You get the idea i think.