The U.S. version still sells enough copies to warrant it not going PH. It's probably selling so shitty in Asia that the only way to get people to buy it was to lower the price.
I'm going to bet that unless Gears takes a huge dive in sales in the near future it wont become a Platinum Hit in the US until a month or two before Gears 2 comes out.
I hate the Platinum sHits boxes. I usually wait for these things to be rumored and go out and buy the original copy. That nice white Oblivion cover is ruined by that shit-ugly frame and spine.
They won't drop it the same way they didn't want to drop Halo 2. Heck, Halo 3 could go platinum hits already, but you know they're not going to do that until 2009.