New File Format For D300?

For the past few years I have been shooting NEF files with my Nikon D70s and displaying/editing them in Photoshop CS2 (Camera RAW 3.7). But I find I am unable to display or edit NEF files captured with my recently purchased Nikon D300.

Do I need to upgrade to CS4, or is there a downloadable update of Camera RAW that will work with CS2?

If I am not mistaken CS2 doesn't support either D700 or D300. I think you need at least CS3.

You'll need to upgrade to CS4 (no sense in going to CS3) or convert your RAW files to DNG (Adobe Digital Negative) files in order for ACR in CS2 to read them.
It's really not a bad way to go at all. You can read a bit more about it and find a link to the free converter here.

Lightroom may also be an answer for you. Depends on your post processing and catalogue workflow.
Capture One also has an excellent RAW converter, and a free fully functional downloadable demo of their product ...

Thanks gentlemen. As suggested by John, I downloaded and installed the Adobe DNG converter. After conversion, I was able to read and edit the DNG files in Photoshop CS2, Camera RAW 3.7.

I highly recommend Capture One. I just starting using it with my D300 and it gives wonderful results - much better than ACR/PS/Lightroom.