So, we've just been discussing the rumored, and long overdue, MacBook Air refresh with a trusted source. This person recently had a working model in their possession for a few minutes and managed to glean quite a bit of detail that would seemingly confirm Apple's plan to announce an 11-inch MacBook Air at the "Back to the Mac" event later today. Here's what we've been told to expect:

* Smaller 11.6-inch display.
* 2.13GHz Intel Core 2 Duo (with a 2.33GHz option possible).
* 2GB of memory in the base configuration.
* No optical drive, naturally.
* Mini DisplayPort, USB, and SD card reader along the left-hand side and USB and power on the right (that's 2x USB).
* The trackpad has been updated to match that of the new MacBook Pros.
* Although smaller due to the 11.6-inch display, it's still about the same thickness as the current MacBook Air.
* A black power key now sits immediately to the right of a smaller eject key on the MBA's keyboard -- the round aluminum power button is gone. A design decision that might support the MBA's rumored instant-on capabilities though our source didn't see this functionality exhibited (possibly because it was running OS X 10.6.4).

Unfortunately, our source couldn't identify the graphics or the storage related to the rumored "SSD Card." So where does that leave us? Well, it looks like a smaller (and presumably, cheaper) MacBook Air originally rumored by AppleInsider is in the bag for a Steve Jobs announcement later today as is a refresh to the 13.3-inch model we broke last week (pictured nekkid above). So check back in a few hours and watch the reveal live, won't you?