EDIT 2:
Vista had to go

Although it's a great operating system in its beggining stage (Read the older reviews below.), I've found out that it has some flaws exactly in those areas where I use my PC most

Particularly, dual display modes & video editing.
When using clone display mode on XP, your PC desktop stays in whatever resolution you are using, and you get the full screen mode of the applications on your tv. For instance, if you use Adobe Premiere, you can see the final look of your video full screen on your TV or any second display. If you play a video in your media player, you get the full screen of it on 2nd display. Well, that's not the case with Vista. It has most awful display settings menu I've seen so far.. Menu's are complicated and confusing. When you set up your display to use clone mode (with TV in my case), it sets your PC monitor in the same resolution as the tv. In my case, the native resolution of my laptop screen 1920x1600 goes to 1024x768, and not a pixel above. On XP, if you use dualview mode, for example, with video projector, it sets the full screen on it automatically. On Vista, you have to manually drag the player/preview window/whatever to the second display (in this case, video projector's screens) and double click to get the fullview. And Adobe Premiere doesn't give a full view on 2nd display, even in clone mode.
So if you use your PC for this tasks... Vista is definetly a no-no. At least untill Nvidia doesn't produce better support (drivers & software) for it's laptop cards, or Vista gets a decent service pack (or 2

)
I liked Vista's new features and speed, but unfortunately I must go back to XP Pro SP2

Any suggestions should I use 64bit versions, some of you had experience with that one? I would appreciate any suggestion.
So long Vista, at least until SP2
Finally, I got my Dell Inspiron 1720. After reading lots and lots of good & (mostly) bad opinions about Windows Vista, I was kind of scared that I will get slow,bloated laptop that will boot for an half and hour and I wont be able to do anything on it.
I must say I'm pleasantly suprised with Vista (I got Home Premium 32bit edition), and I would never get back to XP. Personally, I think all those who bashed Vista for being a sucky operatin system, have never tired it. Or have tried it, but their PC's didn't met the requirements (decent graphic card, CPU etc.), and therefore Vista was awfully slow. My configuration is: Intel Core 2 duo 7500 (2,20Ghz), 4mb cache, 2GB 667Hz ram, Nvidia 8600M GT (256MB dedicated ram) and Vista works flawless. It boots in less than a minute, it opens everything in a matter of seconds, it can be perfectly configured and
organized, it's stable, you can not easily fu*k up some system file like you can on XP... And sidebar is great, it's really configurable. I love everything about Vista

I'm just thinking should I upgrade to Vista Ultimate 64bit version, or continue using this one.
Just wanted to say, if you have a decent configuration that can handle Vista (you can check that with this tool
[link] ), be shure that it's a great upgrade from XP. I highly reccomend it!
EDIT:
I was experimenting a bit, so I tried Vista Ultimate 64bit too.. And I was (pleasantly) suprised again! At first, there were some driver issues (which I highly expected), but I managed to find everything mostly on Dell website, and I googled for the rest. Vista Ultimate 64bit used exactly the same ammount of resources as Vista Home Premium 32bit, maybe sometimes even less (from 32-35% minimum up to 52% out of 2GB ram).
I was highly suprised that software that I didn't expect to work, worked like a charm. I installed ArKaos (it's a software for VJ-ing) that is couple of years old, it worked with no problems. I installed even older software, it worked normally too. There were some talks on the net that Vista x64 has issues with .mov files and Quicktime... I personally didn't noticed any of that. All files and Quicktime itself worked better/faster than on my XP SP2 configuration.
The only thing I found lacking was Dell Diagnostics support. That is available only for 32bit versions of XP/Vista systems, and basicaly it scans your configuration all the time and tells you if newer driver is available online. Since Vista x64 has issues with some drivers (especially if you have some older hardware, like scanner, printer etc.), Diagnostics Support would come real handy. I must say this was one of the biggest reasons I'm going back to Home Premium 32bit version. Biggest one was that I've read that Adobe CS3 has some small issues (that can be fixed by tweaking some files/registry, but I didn't want to risk if they are not resolved by Adobe themselves soon.). Bottom line, I think Vista x64 will be one of the fastest/most stabile system once there is enough support for it (drivers/software).For the first time in my life, I'm pleasantly suprised by Microsoft product
Clubs