I bought a HDD 320GB today and found this thread. It costed Yen 15800 (approx. USD73).
After picking it up, I asked a sales person if or not he knew any foreseeable problems when I change my PC in future (to Vista).
After contemplating for a while, he said, manufacturers attach a "Vista" sticker to boxes when their products can be used with the new OS. So I changed my mind and returned it to the shelf and went to other supplies corner. When I came back to the HDD shelf, they have more 320GB HDD and the new additions have the said sticker. So I bought it.
With or without the sticker, the model code was same. so i think it was just compatible from the very begining.
As my DVD drive accepts DVD+RW only which looks like very minor now and the disc price is much cheaper for -RW than for +RW, I also planned to buy a multi DVD drive but I postponed it. No such a sticker on those boxes.
I learned from Ian's post that the change from XP to Vista is not that big as the change from 95/98/Me so maybe I did not have to worry about it that much. I did not know this when I was at the shop.
Apart from the price, the availability of DVD+RW seems very limited now. I could not find any at this shop. I have to go to another. Really troublesome when your gears are not one of those main stream ones.
It seems DVD drive prices are also declining largely after some manufacturers introduced next generation DVD's (Blu-ray or HDD DVD). Current DVD's are just fine for me as long as they will run on Vista in order to avoid duplicate investment in future.