Needing a new graphics card for battlefield 3

i am wanting to get a new gpu to play battlefield 3 on. i was wanting to know what people think would be the best in my price range. i am willing to pay about 250 max. i am currently using a 1gb 4870 and i know that wont be able to run it great at 1920x1080. does anyone have any recommendations in my price range? i will be running it at this resolution. i am not partial to amd (ati) radeon or nvidia so either is fine.

also should i wait until the radeon 7000 series comes out? i dont wanna get a card and have alot better one a month later for cheaper. i could run my 4870 for a month or two with battlefield if i had to. thanks!

here is my build if thats needed

i7-870 overclocked to 4ghz
gigabyte p55 ud3 motherboard
sapphire radeon 4870 1gb
4gb corsair dominator ram

60 gb ocz agility 3 ssd
1tb storage drive samsung spinpoint