While I think it would be better to have immediate access to a bit more than eight abilities for one character, the fact that you can have up to eight different abilities per party member in the single-player campaign makes it seem like something that I can live with - if what was said earlier is correct. As someone who has played multiple MMOs with lots of abilities accessible all at once (WoW in the past and SW:TOR more recently) and a low number of abilities accessible at once (The Secret World), I've experienced both extremes.
I actually wouldn't mind if my Jedi Sentinel had fewer abilities to use in SW:TOR, because I am stuck (and thank God I have a Razer Naga Epic) with 32-plus abilities that I have had to stick on FOUR different hotbars, along with having had to do an awful lot of keybinding to make the insane number of things that I have to do bearable and manageable. Even with my uber-mouse, this still isn't particularly good for my abused wrists (I work as a book designer, so lots of typing, clicking, and editing - all of which isn't great for my wrists). I use about 20-24 abilities regularly for PVE and more than that for PVP in SW:TOR, and sometimes I want to smack someone over the amount of stuff that I have to deal with. This isn't even taking into account my alts (I have one of each class).
I like TSW's combat system despite the limited number of abilities that I can use at one time, so I agree with what an earlier poster said about TSW. You can save multiple different ability loadouts and change them on the fly - not in combat, mind you. Assuming that you've saved your layouts in TSW, it's quite simple to switch from being a healer to dealing out damage with a few clicks. If they've implemented a similar approach in DA:I, then it might make things less onerous for some people - but who knows exactly how it's being handled. If a similar system is not in place in DA:I, then I'll just point out that it would have been a good idea to make things less onerous for some players - heh.
I feel that the TSW system is actually fairly flexible and fun, and it does spare my wrists some grief when I play. In any case, if this hotbar limit is really such an issue for some people, then at least you now have plenty of time to cancel your preorder(s) and find something more suitable to your tastes.