@Carnivac:
You do have a good point about the low resolution + turning frames making a huge difference on the smaller sprites of yours.
Like I said, in my opinion, it really does depend on the type of game whether or not this feature will prove to have enough weight behind it to justify adding it in. For example, a fighting game (or action game with huge movesets) would prove very difficult to do separate sprites for both sides of the character for every character (including enemies that look similar to the player-character, to keep visual style consistent, which in an action-fighting/beatem-up game could prove very painful). It could still be done for a small game (or a large game with a large team), but I think common-sense dictates that it's not practical (or feasable) in quite a number of more complex games with realistic budgets.
Though, with that said, I also agree with you that, if it can be added without much trouble in both art and programming, it really should -- especially in games with more simple-to-make art-styles that allow you that extra time to add-in visual flourishes here and there. To me, that sort of stuff really rocks and makes very simple games feel a lot more worthwhile to play.
@BioLink:
Not bad -- the new chars look pretty great. Reminds me a lot of megaman x, just with a mini-mecha.
Two things though -- I would suggest on the right-facing sprite to put some indication of his hand on top of his gun-arm to show that he's aiming it / holding it steady and not just pelting bullets, and perhaps making his gun a little longer to help the silhouette a bit and fit with the standing frames better. Other than that, they look great.
