Just an update, still waiting for my fast SD cards to arrive, Amazon says they'll be here by Dec-11, can't wait to see the results, just need to eke out a few more MB/s to get continuous 1280x720p @ 24fps RAW!
IBIRRU, I answer some of your questions below, but I barely know how to do some of the basic things in ML and only on the 650D, so maybe look for additional verification of my answers.
YOU WROTE (in black) - I ANSWERED (in red):
I need to know before to buy the 650D (for sure)
1) if the mlv_play module works (if it's possible to review the raw video stored in the SD card) - in 500D is not working
Yes, you can preview RAW on the camera, but not at proper frame rate, it plays back slower and of course there will be NO audio, as it doesn't record sound in RAW mode.
2) if the liveview is working during raw video recording - in 500D is not working
Yes, live view works whilst recording in RAW.
3) the maximum x_res and y_res and frame rate obtainable (es at 1024x1024 what is the max frame rate? Is it possible get 30 or more fps?) in 500D there is a 508 y_res limit
1024x1024 for RAW recording is not an option from the preset selections presently available (developers could probably add it, but this is a question for them), either way I don't think you'd get 30fps RAW @ 1024x1024 as the the highest frame rate being captured right now is 24fps @ 1280x720p and only under the best of conditions (fast SD card, all other features turned off, etc.), but you could shoot at slightly lessor settings to get your 30fps and then up-res and crop in post??? Considering its RAW, you'll have the detail to do it and it'll probably still look pretty good, better than H.264 compressed native video output anyway.
4) Intervalometer and bulb timer are working? - I use them a lot
I haven't tried this, but I believe it's working from what I've read in other posts.
5) LCD sensor remote is working? - I use it a lot to substitute the remote shutter
First off, I believe you mean IR (InfraRed) remote sensor, but either way I have no idea, I suggest you search the forums for an answer or post the question separately in a more appropriate thread with a similar topic.