when will mb374 model(mbp 13inch mid2010) surport win8? or just not surport forever?

Welcome to the Apple Support Communities

If it's not supported yet, don't expect that Apple will release drivers for your MacBook in order to install Windows 8.

However, note that your Mac is compatible with Windows 8 because you can run it, but the problem is that Apple doesn't provide the drivers you need for your Mac, so performance will be poor and hardware won't work correctly

Macinda wrote:

as title...

just when..

Aparently, there's a workaround to this problem in here:

Found a way to get BC 5.0 working on a "non-supported" 2009 Macbook

And here, if you are in OS X 10.8.3:

BootCamp 5 on a 2008 1st gen Unibody MBPro

I am not responsible for any issues that may arise from this method. Try at your own risk and good luck!