I can understand the issue the author discusses with making tabbing MRU, but I think preference for this behavior differ between users. I have no trouble internalizing the order of the last few applications (or browser windows), thus MRU is the best for me. I'm likely to have several windows open, and it's fastest for me to be able to quickly bounce between a constantly-updating MRU list.

Let's take the "Order of Application Opening" model: If, say, I had opened iTunes between a messenger program and a browser, and I were flipping between browsing and chatting, I would think that iTunes, being a background sort of application, would require me to remember to double-tab every time I wanted to bounce, requiring an extra button press and an internalization of that data instead. (As well, wouldn't the static list then require me to Alt-shift-tab every time I want to bounce backwards? I certainly could tab forward and wrap around if I had only those two applications open, but that's rarely the case, so it seems that a static ordering would only ever hinder me. Keep the static order to the taskbar/dock where it belongs!)

Somewhat related: Something I've always wanted is the ability to navigate tabs in Firefox with CTRL+Left/Right-arrow, similar to the CTRL+# to get to a certain tab number. I looked around once, perhaps a year ago, to no avail, and haven't searched since. Anybody know of an add-on that adds this functionality?

edit: BoppreH, in another post, mentions CTRL+[Shift]+Tab. I'm basically asking for this functionality, remapped to CTRL+Arrows (It's more comfortable this way, rather than isolating the button presses to one hand)