One of the reasons Megadeth has lasted as long as it has is Dave Mustaine's commitment to evolving the band's sound. And it looks like Mustaine has another trick up his sleeve.

In a new Facebook posting, the vocalist asks his followers, "Any ideas for a guest singer on a track? I have a few ideas, but wanna know what you think." The timing of the posting is a bit of a head-scratcher as Megadeth recently completed recording on their new album and are currently in the mixing process, so it's not known if the idea of having a guest vocalist on a song is meant for a future recording or something that might turn up on their next album.

In the short amount of time the posting has been up, Mustaine has already received over 3,000 comments from fans with suggestions such as Anthrax's Joey Belladonna, Metallica's James Hetfield and Down's Phil Anselmo among those frequently mentioned.

Megadeth have been holed up in the Vic's Garage studio in San Marcos, California over the last few months with producer Johnny K overseeing the effort. Bassist David Ellefson recently stated, "Really some great, great songs taking shape at this point in the recording process. I told Dave [Mustaine] today that one of them totally reminded me of the earliest stuff back when we first met — fast, rippin’ and fully bringing the REAL old-school Megadeth sound!!!”

An official release has not been revealed, but it's safe to say that Megadeth's new album is on target for a 2013 street date.