Actually, reading this makes me concerned for Mass Effect 3 on a lot of levels.
To be brutally honest, the changes to the combat system were a big "surprise" which seems to be regarded with a large about of negativity from RPG fans and fans of the first game. Namely the changes catered to the "shooter" crowd who are incredibly vocal. This resulted in some high reviews, but a lot of the sales were a spillover from the first game (which had a LOT of fans especially if you consider the used market).
It's noteworthy that the game has been being flamed pretty hard core for becoming an action game by a lot of the players themselves. You even have guys like Grahm Stark making jokes about it and the reception it's ACTUALLY been getting here on The Escapist in his ENN segement (with the reduction of role playing elements and such).
To put things into perspective let's look at another action-RPG series: The Marvel Super Heroes RPGs. These started out in the X-men legends days as being a pretty hard core RPG stat wise. However each installment reduced the RPG elements. Marvel Ultimate Alliance got a pretty big sales boost by being a ganeral marvel product, however someone involved in development got the same impression that Bioware is getting now that it was the reduction of RPG elements and becoming an RPG in name only that was selling the game. Enter Marvel Ultimate Alliance 2 which was a glorified brawler, and which was apparently not the success that was expected because of this. A lot of people took a "wait and see" approach based on some of the things they were saying, and largely because of the downward trend in the RPG aspects.
Bioware is interestingly enough "surprised" by the massive success of "Dragon Age: Origins" which is a number intensive RPG of the so called "old school". Indeed that is why it succeeded and it's also the elements fans want to see expanded upon as opposed to seeing it turned into more of an action game.
With Mass Effect 2 I think they really aren't 'getting it', and are listening to the wrong people. The "Shooter" combat in ME 2, along with the gutting of the inventory system, mission based exps (as opposed to being able to earn exps by killing stuff) and other aspects are things the game succeeded IN SPITE OF, not because of. Had Mass Effect 1 been on the wrong track it wouldn't have succeeded like it did, and ME 2's success is very much a result of the first game.
It's also noteworthy to point out that a lot of people who played ME1 were rather irritated by desicians to limit the potential impact of the first game on the second "for fear of alienating new players" which has lead to a lot of skepticism about a third installment, as well as irritating people who spent a LOT of time replaying ME-1 before the release of ME-2 to get things "just perfect" based on what desicians they wanted to carry over, only to find that only a tiny amount of things actually mattered, which wasn't quite what many of the players wanted.
Rather than considering Mass Effect 2 a success, I think Bioware should consider it a stroke of good luck that the hype from the first game was so powerful. Rather than embracing what they did with ME2, they should be taking a few steps back and consider how to improve elements from the first game rather than scrapping them entirely, and keep the game intact as an RPG experience rather than a second rate 3rd person shooter with a few customization elements and a lot of dialogue and cut scenes. For example people hated the inventory system from ME1 because frankly the loot wasn't all that exciting. There were only a handfull of items in the game all told, and you simply found better versions of each "brand" and once you knew what brand to look for everything else was simply clutter waiting transformation to credits or Omni-Gel. A disappointment considering the itemization in the "Knights Of The Old Republic" game which made the loot comparitively more exciting. In fact as a spiritual succesor to KOTR Bioware should have been looking towards that for an example of what a lot of the people wanted from MAss Effect (more items, more possible equipment slots, etc..)
I'm sure there are those who will disagree (people who dislike RPGs, and/or love shooters mostly) but this is how I see things.
Only time will tell what happens, but I think Bioware needs to look beyond the actual sales here and at what a lot of the core fans have been saying in forums and such, and consider that a lot of those people might not lay out the money for the newest game after this one, I suspect if things continue along these lines you'll see a LOT more people taking a "Wait and see" approach to ME 3 than running out and going "Oh yes, I MUST have it" and making allowances to buy it months ahead of time.