Finger of Frost in 3.0.3
In order to get the same effect from Fingers of Frost as from actual frozen targets, we would have to set up the spell the same way as freezing, so that you could sneak that Ice Lance in between Frostbolts. Right now you get 2 big hits from Fingers of Frost, which you rightly want to spend on Frostbolt. If we changed Fingers of Frost so that Frostbolt always broke it, then you would want to get that Ice Lance in there, but your overall dps would go down. We'd need to compensate Frost some other way for that nerf, and it's the kind of thing that might not be popular with the mage community because we'd be nerfing Fingers of Frost's damage potential in order to force you into using Ice Lance all in the name of more interesting rotations. (Obviously we're not that nervous about making unpopular changes when we think they are warranted, and overall encouraging players to use different kinds of spells is a good thing.)
Of course if we also made Fingers of Frost (or Ice Lance) better, then we're just going to have problems with Frost in PvP.
Frost's PvE dps is very good right now -- if anything it's a little closer to Fire than we predicted. If Frost starts to fall off for any reason, that would be a good opportunity to revisit FoF to see if we can get more of the behavior you're describing, because ultimately I agree it would be cool to see more PvE Ice Lances.
Source: http://blue.mmo-champion.com/4/11829519585-gc-the-shatter-combo-problem.html