i just want to address a few things that were said, more or less, in the OP. If we are on a tangent about opinions, i'd like to say that it's my opinion that the point is mostly being missed. Old School Dungeons and Dragons was a War Game modded to fantasy themes on hex maps, and was straight up dungeon crawling. The idea of RPG came not from classes and rulesets, but the spirit of storytelling.
Icewind Dale was based heavily on 2nd Ed Advanced Dungeons and Dragons, along with Baldurs Gate, both set in AD&D's Forgotten Realms campaign setting. Bioware did not choose these, in my opinion, because AD&D tabletop rules would make a fun game. They choose them because the setting makes for fun storytelling, and thats what Bioware is all about. You ( OP'er ) mentioned a ruleset that took years to perfect. But the AD&D rules is still going through revisions, it is not perfect. Bioware has done what TSR and latter Wizards of the Coast only scratched the surface of, and thats provide a means to rewrite the system as you and your fellow players see fit. Bioware's toolsets allow for customization the likes of which isn't really included in a Players Guide, Gm guide, and Monster Manual.
But at the heart of this, Dragon Age Origins, is where we need to focus on. Bioware has said that they didnt abandon the venerable Forgotten Realms setting so much as be inspired by it... the spiritual successor to Baldurs Gate. Does that really mean they wanted to focus on building a ruleset? If that was their aim, why not just take the new 4th Edition ( or is it 5th ed now ) rules and build a game around that? They were inspired to build something fresh, a game that was not weighed down in its own dogma. The idea here is storytelling. And with a new setting, and a powerful toolset, we ALL can build this game franchise. Bioware stated that they named it "Origins" for several reasons. It is a starting point of the new intellectual property, but also they wanted to return to where this all came from. The inspirations of imaginative storytelling. It may be litteral, true, but the father of all these settings and games and complex classes was Elves and Dwarves, Wizards and Warriors, Brawn, Stealth, Magic, and Subterfuge. Its a return to RPG's roots as much as it is a return to the origins of many of the people who created this game, if i had to guess. If someone wants a convoluted mess of classes and oddities, Final Fantasy and it's ilk may be more their speed. For me, Dragon Age feels like a walk down memory lane, and i havent even played it yet.