Rumor: Sonic Playable in Super Mario Galaxy 2

UK magazine Ngamer reports that a "trusted source" inside Nintendo has revealed Sonic will be a playable character in the upcoming Super Mario Galaxy 2.

Ngamer reported the information in a Twitter post, saying:

"We've just had some shocking news from an inside source at Nintendo: Sonic will be a playable character in Mario Galaxy 2! Wha?"

The magazine followed up by revealing where Sonic will show up in Galaxy 2:

"More teasing from our insider: Sonic levels will be in 'Green Hill Galaxy'."

Ironically, I suggested the idea on The Wiire Podcast Episode 159 that we could see other franchises show up in different galaxies within Galaxy 2. I had figured those would be Nintendo-owned franchises such as Pikmin and Pokemon, not Sonic.

Unfortunately, without comment from Nintendo or Sega, this is likely to remain a rumor. With yesterday's announcement of Sonic 4 (and new leaked details today), however, how likely would it be that we see Sonic team up with Mario this year?

Let us know what you think in the comments below!