I would recommend trying to maintain Plat status for 2012. Getting that last 21k will be tough but nice for the following reasons:

- AA typically gives a 'soft landing', so even if you don't fly them at all in 2012, you'll still get Gold status (not guaranteed)
- Having Platinum while you burn miles for an intl trip, very nice to have Lounge access
- Get the double miles (PLT bonus) while you can
- Companies change preferred carriers. I was part of a >100k workforce too, and we were United for 2 years, then AA for 2 years, then back to United! Frustrating, but it happens.