Anyway, I think it's soon to discuss on this marginal detail.
With the gained space from the unification of the titlebar with the tabs, breadcrumbs could be added, which, beside having the function of showing you the path, could provide a quick access to folder and files.
If you don't need the quick navigation and want to keep the extra space, displaying the file path in the status bar (when there is no status message) could be a solution.
But, if I eye-tracked myself I'd admit that it perhaps doesn't matter... as long as there's some means of seeing the full filename somewhere.
There's a lot of empty real estate in the status bar, so you guys are starting to change my opinion about this. However, note that the display file path in status bar feature has very few votes. (Want a tabbed title bar? Want ybakos to stop whining? Vote for the 'display file path in status bar' issue and note the 'dependency' with this 'unified bar' thread.)
As for convincing Jon... you're on your own. In my opinion, implementing tabs in the title bar and preserving the tabs when going full screen, etc will take some work. (Hey you, buy a license!)
Customer support service by UserEcho