Differences between 30GB iPods with different Part Numbers?

I bought a 30GB iPod last July, Part No. PA002LL/A. It was stolen in December. I just got my new 30GB iPod and noticed it had a different Part No., PA444LL/A.

They're almost the same. The headphones with the PA444LL/A don't seem quite as nice and they didn't come with the little black foam pads that I got with my last iPod (PA002LL/A). Basically, the headphones seem to be a downgrade.

Also, maybe it's just me forgetting, but the touch wheel seems to be a slightly darker gray on this new one...

Anyone have any info about this?

Thanks.