So after reading a little bit on the forums for any kind of heads-up info I could potentially use, I noticed some people talking about there being savegame transfer technology in this series, a-la Bioware's tried-and-true formula.

My question about this is what kind of benefits do you gain after beating the game and carrying over to TWII? Is it just the outcome of the story, or do you also carry over loot and/or abilities? Romance plotlines? Any info would be great and much appreciated.

I heard your steel sword, silver sword, and raven armor transfer. Not to sure about story, though originally I think CD-project said that depending on your actions in part 1 doing certain things in part 2 can be easier to do, but all choice options are available regardless of W1 save choices or even having one.

It is a neat feature which helps tie the games together a bit more, but it doesn't do anything significant. Equipment carried over will be outdated by the end of Act 1. Dialog/event changes are minor.

--Edit--
About romance possibilities. I have heard that it completely ignores romance choices from the first game, but I have not personally tested this.

About gear you carry in the new game your silver and iron sword and armor, as posted before.
About the story ive read that many of your choices in TW1 will have an impact in TW2, in example you can encounter again an NPC if you saved him in TW1 or you may have more choices in some situations, anyway what ive read on the net about it was quite vague.
Personally i think ofc the game experience will not have any relevant difference for a new gamer or starting with a TW1 save game.

Edit:
about the swords... you will import your swords but they will be rebalanced in TW2, so at the end they are just abit better then the standard swords given without the TW1 save game, they totally miss the stats like "+50% dmg" or "+ 30% stun" etc.
At the end you got only a different model of the swords in case, more then a real bonus in combat.

It does not transfer the Gvalchir steel sword, it should be noted.

I'd think this would be true since, as far as I can see, Shani doesn't appear to be in TW2. I'm not saying that having completed TW2 but simply as she's been in no promotional artwork, videos or even slightly mentioned in relation to TW2 at all. I'm yet to complete TW1 so there may be some very good reason for this that I'm yet to see for myself.

Either way, it's still pretty annoying since my Geralt currently seems to be practically married to Shani and looking after the creepy kid with her, while Triss is pissed off with him all the time. It's going to be odd going into TW2 and having Triss possibly act like nothing happened and to see Geralt's makeshift family vanish into thin air.

"It seems that the Mahakaman rune sihill [...] should also transfer, but it does not. "
Seems it is, because in my game it was transfered.

Me too, I can confirm that.

I would say that, if you've recently finished or plan to finish TW1, do keep your endgame saves and transfer them to TW2. It won't make a huge difference, but you will notice a few things you might not see otherwise.