enzo matrix :
Mostly correct and I agree the i3 has these features and whatnot that the radeons lacked before the 5xxx series (which currently there are still no integrated versions of), but I wouldn't think them necessary.
I dunno about you but I have no problems running 1080p blu-ray on my desktop with integrated radeon 4200.
The power efficiency in the article you mentioned is for the phenom II series. The Athlon II, although still drawing more power, will not draw nearly as much as the phenom II series. If you are really worried about power consumption, you could got with an Athlon 240e. But only if it is less expensive than an i3 because otherwise it wouldn't be worth it.
Yeah totally right about the hard drive. My current drives are an old seagate and a relatively new 1TB WD green with only 8mb of cache. Great drive.
Oh, I definitely had no issues playing blu-ray on my old integrated 780G (the HD3200) or the newer 785G (HD4200) - both worked great. I actually had three issues with them, though.
One, I bought a new stereo that supported Dolby TrueHD and DTS-MA (and a plethora of other things I'll probably never use). So, I had to upgrade if I wanted that sound since the integrated ATI graphics still can't handle those audio formats. If you don't have a stereo that supports those, then absolutely - any 780/790/785/890 will do Dolby Digital and DTS just fine. I ended up getting the 5570 when it came out.
Two, with my Athlon II X2 240, 4Gb of memory, a 785G, an internal 160Gb drive and an external 1Tb Phantom Green drive, along with Win7, my PC was using around 230W at idle. My i7 heavily overclocked with 12Gb of memory and 3 HDs only uses 250W at idle. I just thought that seemed excessive for an HTPC that was on 24x7. Switching to the i3 530 on an H57 mATX board (using the same PSU from my old build, mind you) dropped idle power to the low 80s. In the grand scheme of things, it doesn't make that big of a difference, but over the course of a year, that's a lot of saved electricity $.
Three, the HD3200/HD4200 didn't quite have the level of graphics filtering (AA, Stream, etc...) that I was hoping for, though the 4200 is quite a bit better. That said, I'll be honest and say that overall crispness seems to be better with the i3, but I'm not convinced it's not all in my head. I don't think most people would even notice.
The 5xxx discrete cards, especially the 5450 and 5570, are PERFECT for an HTPC if you want to go AMD. I swear there was something the 5450 was lacking (and IIRC was just a minor issue) but danged if I can find the article where it was detailed now. I know it was why I ended up going with a 5570 when they finally came out. THs review didn't specify it, so I'll go ahead and say the 5450, at $50, is perfect if you need the audio capabilities that BluRays usually contain.
It really just depends on what kind of stereo you're going to hook it up to and what sort of audio it's capable of decoding, how picky you are with the video quality, and whether you're concerned with power usage or not. Even a 240e using a dedicated lowly 5450 is going to use more power than a i3, it will be slower than the i3, and end up costing about the same ($60 CPU and $50 graphics card, or $120 i3). I'm totally cool with either one. If it wasn't for the overall flakiness I was experiencing with BeyondTV for the past year on my Athlon II setup, I'd still be using it and not knowing any different. I'm just totally ecstatic about the i3 and how nicely everything just works.