Incoming buff for Frostbolt 12

Such power we have here at WoW Insider! I posted early this morning about Frostbolt 12 doing less damage and costing more than rank 11, and now it's going to be buffed. Vaneras, bearer of good tidings:

• We have received quite a few reports regarding the Rank 12 Frostbolt not doing enough damage when compared to Rank 10 and 11. To address this issue we plan to change Rank 12 in the near future, hopefully to be implemented with the next patch already.
  
  Frostbolt rank 12 should get improved and receive approximately 20-25 additional damage points for max damage

This looks like a pretty small buff to me. That makes sense in theory, though, since I finally got my head around Tseric's argument from yesterday. Basically, the argument is that rank 11, as a book drop, was meant for uber 60s, whereas rank 12 is meant for normal 63s. If they had as much of a jump every time as they did between 10 and 11, Frostbolt would soon get pretty imba. Let's compare numbers, just for fun:

• Rank 9: 368 average damage, 225 mana (1.64 dpm)

• Rank 10: 446 average damage, 260 mana (1.72 dpm)

• Rank 11: 535 average damage, 290 mana (1.84 dpm)

• Rank 12 (buffed): about 554 average damage, 300 mana (1.84 dpm)

So there's a jump of 80 damage or so between 9 and 10, 90 damage between 10 and 11, and...10 damage between 11 and 12? Seems weak. But! There's one more factor to consider: levels. There's a small level gap between rank 11 and 12, so you might expect a small damage bump. Anyway, for one more bit of perspective on the issue, here's a graph I made of average damage vs. level of the different Frostbolt ranks (starting with rank 8). The line in the middle is a linear fit, so you can see that Rank 11 is significantly above the curve, and the new rank 12 is right back on it.

What do you think about this small buff? Too little, or just right?