The introduction of runeforging to the Wrath Beta was a bit of surprise and slightly unexpected. Instead of rune swapping -- the idea of being able to change the nature and configuration of the runes on your runeblade -- Death Knights got a solid 2 Unholy, 2 Blood, and 2 Frost runes. Runeforging itself became a weapon enchantment system whereby Death Knights could enchant their weapon with various special procs and buffs for various situations.
There has as of yet been no sign of an ability to swap runes, and Jayde, aka Jadefury, recently asked if there were still plans for one. The short answer, according to blue poster Ghostcrawler, is no.
The long answer is perhaps a bit more complicated, and reinforces Blizzard's stated goals with the Death Knight class role and the new runeforging ability.