My question to you would be:
Are you experiencing any problems or slowdowns with your current computer?
If the answer is no, there is no need to upgrade yet.
Re: drive failures.
Always back up your importnt data. These days its so simple and cheap to pick up a usb harddrive and backup onto that as often as you need. You could also just upgrade your drive and use the old one for backup.
On HD playback. It seems that HD decoding is going to reside on hadware on the video card. If you need/want to do do HD playback via comuter, pick up an hd drive (there is a HD-dvd/ \Bluray combo player out there for about $300 now)and one of the new video cards made for hd playback.
The advantage of waiting to upgrade until lack of computing power becomes an issue is that stuff keeps getting,bigger,better faster and cheaper at an amazing rate. The longer you wait now, the longer it will be until your next upgrade.
For example, until last month, I was quite happy running on an old P3 500. I upgraded because I wanted to do dvd playback to a newly purchased high def. display and couldn't do that with my P3. I skipped an entire generation of cpu because I just didn't need it.
Once the high def format war finishes, I will add an hd player and add a graphics card with hardware based hd decoding.
If you really want to upgrade, you can always put your old drive on the new system and use it for backup.
So, if you don't need to just yet, wait.
In another year, Intel will have moved to a 45nm process for all its cpus (smaller, better and faster while using much less power than your p4), all the motherboards will have updated to the new processor format, ddr3 memory will become more mainstream and affordable and most of the early driver problems with hardware decoding of hd material should be resolved.
Fred
