I'm really liking the new tabs in 4.5, but I have a couple of thoughts on their behaviour for you.
Would it be possible to make the Select Next or Previous Tab command (Command-{ or Command-}) wrap around the end, so if I'm in the rightmost tab, and press Next Tab, it cycles to the leftmost tab? I used to use Exposé to quickly switch between Contact Sheets in 4.4, and the keyboard shortcuts are now quicker most of the time, but it I only have two tabs I sometimes lose track of which one I'm in, so this change would mean that either Command-} or -{ would always switch to the next tab. Safari's tabs behave like this and it's very convenient.
Also, would it be possible to somehow have a choice over whether PM opens new folders in multiple tabs or a single tab? Specifically, I'm thinking of when I drop folders onto the Dock icon, which is my usual way of opening folders as I tend to use the Finder more than PM's Navigator or Favorites. If I drop multiple folders onto PM, it now opens them into multiple tabs in the same window, which is usually ideal. Sometimes though it would be nice to have them all open into the same tab, as this would be quicker than right-clicking each one individually in the Navigator and opening each one into the current contact sheet, especially if it is many folders. Ideally a keyboard choice, for example by holding down a specific key or not as you drop them onto the icon to define how PM handles them, but I suspect that would be handled by Mac OS rather than PM so may be outside your control. I can see a preference setting would be able to affect how PM handles multiple folders opened at the same time, but that would not be so useful on a case-by-case basis. Would something like a Combine All Tabs command be possible, which would create a a new Contact Sheet replacing all the tabs in the current window with a single one containing the contents of all the separate Contact Sheets?
Sam.