I think that getting rid of multiple attacks is a terrible idea - at least if you follow the SWSE model.
(I think it's an awful idea, period - there's something a lot more satisfying about actually being able to roll multiple attacks and allocate them as I like, then just getting a damage bonus equal to 1/2 character level, and it's a huge milestone in character advancement when you get that additional attack, but that's neither here nor there.)
You see, if they actually stuck to "only one attack per round, unless you take the special feats that let you make two at -5 or three at -10 - no exceptions" and had various other feats simply modify what you can do with your attack, how much damage you can do, what your threat range and reach are, etc., then it could have been fine.
What they did instead is create exceptions right from the start - specifically, a TWF feat tree that lets you attack twice at -2 at level 6 and at no penalty at level 11. In a system in which everyone eventually gets multiple attacks anyway, off-hand weapons do low damage and always have at least a -2 penalty to hit, TWF is not an issue.
In a system in which everyone is normally limited to one full-BAB attack per round (which makes an extra attack at or close to your full to hit bonus vastly more valuable) and already has feats like "Rapid Strike" which abstract taking an extra swing as -2 to hit and +1 die of damage, it's an idiotic and inconsistent design choice.
Anyway, if they do something similar for D&D, you can bet your ass that it won't take them long to start putting out supplements that will give you new feats, powers, PrCs, racial abilities (or whatever else they come up with to sell splatbooks) designed to get around the limitations placed on how many attacks you can make - and you'll just end up with a huge power disparity between people who are optimised for multiple attacks and those who aren't. (Anyone around here play the KotOR games? Perfect examples of what happens in a d20-like system when you make one attack per round the default and then introduce feat trees which eventually let you make multiple attacks at little or no penalty. People with double the attacks end up - surprise, surprise! - vastly more powerful.)