Has anyone bought one of these?

Has anyone made an assessment of its media potential as compared to (say) a Macmini?

interestingly i can't find a single word about cooling system? (my idea would be to use few as render farm for example)

Here's a PC Mag reviewof the Studio Hybrid: http://www.pcmag.com/article2/0,2817,2326614,00.asp

Power consumption on the test system is within a few watts of the comparable mini, with the 2.1GHz/2GB model pulling an impressive 44W under load.

The cheap Dell Studios do ship with reasonably sized hard drives and DVD burners. The HDDs are still 2.5" notebook models spinning at 5400rpm (like the mini), so don't expect desktop hard drive performance.
The SH supports 4GB of RAM, which is certainly far preferable to the mini's 2GB. The intel chipset-integrated video on the SH is slightly more recent, but both steal system RAM, and in practice I'd anticipate dismal full screen 3D performance either way. Dell also gives you an integrated card reader.

Apple wants to upsell you to get a DVD burner and a hard drive >80GB, but you Do get OSX and Apple's value-added programs, not the cut-rate Vista Home Basic shipping on the cheap SH's.

Check out a back view of the Studio hybrid - that's probably a 60mm fan doing the ventilation.

I'd assume that the mini will either get discontinued or thoroughly upgraded at one of the next major Apple conferences. If you cannot wait for a smallish desktop I'd check out a small form factor dell Vostro or HP when they go on sale (gotapex.com, slickdeals.net coupons).

For HTPC purposes you might take a look at the HP slimline models PC Mag references.

Don't buy an Atom if you plan on handling media!

for home use, say i wanna use it as web server and htpc at the same time, what would you suggest? (what OS, what remote? ect)

for htpc part:
- fully compatible with SD and HDTV tv sets
- powerfull enough to play 1080p
- software must have great subtitling skills
- must play DVD ISO files as interactive DVD

for web server:
- basic server like lightTPD or apache + php will do just fine

Is there one free PCI slot?

smok3: You might try asking that question on Doom9 or another HTPC oriented-board. I'm just not experienced enough with HTPC specific builds to answer your question authoritatively. I can tell you to avoid the Atom like the plague for media handling (although most anything current is a decent light-duty home server), especially 1080p! The arstechnica, anandtech and hardocp boards likely have subforums that might specialize in such recommendations. Doom9 is no doubt an excellent resource as well.

My experiences with home-brew HTPC has been relatively negative, largely due to ATIs truly horrible TV tuner drivers (their video card drivers on the other hand, have been at least as good as nvidia over the last several years IME). The hardware seemed quiet good (theater 550 SD tuner chip), when I could get it to work. OEM builds may be preferable because they actually have to work correctly out of the box. I believe dual tuners are supported properly under Vista at least, but you might check that too!

Cutter: The Studio Hybrid is too small to fit a PCI slot in, I'm afraid. All upgrading other than RAM and Hard drive is going to be external.

for anyone considering purchasing new computer hardware any time soon: Hold off if you can! Intel's next generation "Nehalem" core has been announced, tested and detailed and is supposed to ship within months. It's a big step up from the already impressive Core 2 Duo, as it finally incorporates and on-die memory controller (which helped make the original Athlon64 so poweful). Intel is upping the ante to a 192 bit mem control design, meaning you'll need 3DIMMs for full peformance. Consequently I'd expect all sorts of new announcements very soon.