I think confusion between "Sale" and "Clearance" is important to address too. I think we'll see multiple sales... "BOGO", "2-for's", and the like... I think that'll be a common thing up until a clearance.
To address why there wasn't a Saga Clearance, technically there was... First though, there was a "buy-back" situation though, and then there was actually a 2nd "buy-back" situation. Hasbro did that once I believe with Episode One though, and later in the line's life.
After the buy-back the figures wound up at KB in droves... Or so the story goes. Hasbro did a lot to make TRU and WM happy during the Saga glut though... I remember people boxing those figs up in droves at WM. One day they had a wall of useless stuff, the next they had nothing, or even had semi-new stuff out. Some of that though, as I recall, was even "old" by the time it got out to the shelves. Target was more conservative, as always, and avoided that situation.
With this movie, it's tough to say if Hasbro will bite on taking any of it back again... The line is theirs to sell after this film, not the other way around, so I'm not sure how they'd handle appeasing retail shoudl ROTS see massive gluts.
I wouldn't say things are flying off shelves here though, by any means, they just are doing better than Saga did... In my neck, people werne't in aisles, kids weren't interested, and Saga tanked... ROTS I'm seeing different things, but that doesn't mean I'm not seeing lots of figures on the pegs, or that I'm seeing stores restocking constantly. If I was, I'd be able to find those later #'d figures that are aggrevating the **** out of me.

I will say though, that for an initial push, this line's doing better than Saga did I think. I've seen stores restock since 4/2... I didn't see that with Saga in its first week or so... Hell, the WM I frequent most restocked once since 4/2, but with Saga the only thing they restocked was the TIE Bomber they held off on putting on the shelf till MM... The rest just clogged the pegs for months. It was really quite sad.
They're stuck now though with the typical stuff every other store has.
I will say if you're wanting to army build, don't wait. Clones, RG's, and even the basic battledroid are moving. I find C1 Clones sporatically with BD's, but that's about it. All that other stuff is hot property at the moment. Toy Show had Pilots, Commanders, etc., for $15 - $20 each. Pissed me off to see all the scalping sacks of dung selling what I think I can rightly assume is my area's supply of the figures I wanted the most... And lying through their sporatic, yellow, gnarled chicklets they call teeth about these being "limited run" items, "variations", and "rare"... Buncha dickheads.