If you think about it:
Blood Frost Unholy
Rune "strike" Death Strike Obliterate Scourge Strike
RP ability DRW Hungering Cold Gargoyle
Back up? Heart Strike Howling Blast Obliterate?
Before you say that Frost Strike is Frost's RP ability (I'll get to this later), think back to 3.0 - what was at the bottom of the tree? My point is that the Frost runic power ability is kind of a wash out with only pvp utility (since who cares about trash and bosses resist it).
We do, however have a powerful, comparable ability as far as ass-kicking in the form of Howling Blast. Unfortunately this also uses up runes we'd otherwise use for our main strike - something the other trees don't have to deal with. Consequently, we're forced to rely on a 3/20 chance that we'll get to use this ability (because if you're dealing with a boss, obviously the runes should be centered towards Obliterate)
Runic Power: Let's consider the frost tree for a moment - with talents like Runic Power mastery and the other one that increases RP generated from spells, clearly our tree is about gathering and utilizing RP... so why don't we have something more interesting than a single target poke? (Cuz let's face it, Frost Strike used to do way more damage before).
Proposal: Make Howling Blast cost 70 RP, change it's CD to 30 sec. and let it's damage be the as it is now, but increased by 5% for each disease and for every 10 additional runic power. Fully loaded, it would hit for 140%. For me in full T9 and some ICC loot, it crits for about 8.5k => fully loaded, it would hit for 11 - 12k. Considering the numbers that scourge strike and rune strike were dishing out (and considering that it's not modified by ToT), this is equitable. And it would allow you to utilize one of the amazing abilities in the frost tree.
Frost strike:
Frost strike is another poke that's there for you to do something when your runes are on cool-down, but more often than not, your RP is just sitting there. It's not like Blood where it at least contributes by upping the damage of your Death Strike.
For the people complaining about how they need Frost strike to fill the gap, this would be mitigated by altering Frost strike. Rework the spell such that it replaces Obliterate (in ability and in cost) just as Heart Strike replaced Blood Strike. Let it be buffed by stored Runic Power to encourage saving up for that big blast. Frost loses the ranged versatility of Death Coil because it uses its RP for another ability - bring it back! IT and HB can't hit as far as DC can, so why not give frost DKs a way to properly use our one real ranged ability?
Thoughts?