Good morning corlenbelspar
Well in my opinion I would not do this for a couple of reasons. But like I said this is my opinion
Windows 2000
"As support for Windows 2000 ends on 13 July, 2010" so the only updates you will get will be before 7/2010.
W2K was fairly fast but could be temperamental with drivers. I don't know where you will find drivers for a NETBOOK which ever netbook you have. I would stay with XP. There is a really good possibility it will run worse with W2K than XP.
Windows XP
"Even though we ended the sale of Windows XP on October 22, 2010, we still plan to provide support for individual users and businesses until April 2014" just for the updates alone I would not downgrade to W2K
Both OS's were built on the same NT kernel but XP drivers do not always work on W2K.
You cant not install newer versions of IE on W2K, most software will be written for XP and not W2K. A lot of companies do not offer support for any OS before XP.
Don't get me wrong when W2K was out and running it was fairly stable, quick, clean looking etc. Well hope this helps you on your decision, Mike