Dr Horribles Sing-Along Glee

According to The Ausiello Files over at EW.com, Neil Patrick Harris – Dr Horrible himself – is on the verge of being reunited with Joss Whedon for another sing-along extravaganza. And no, we’re not talking Dr Horrible 2.

It seems that the producers of cult hit series Glee are on the verge of signing up Harris to guest star in the episode that Joss Whedon will be directing.

Ausiello points out that there is a possible snag, because Harris is currently appearing in How I Met Your Mother: "CBS has to OK its [his] appearance on Fox’s breakout hit. But at least since HIMYM and Glee are both produced by 20th Century Fox, there’s no conflict on their end."