Yes, no?

I'm thinking the last level. And it will be epic.

yeah, in Firefight mode AFAIK.

in the campaign ? I say no way.

No, I think we'll probably see him in the end leaving Reach on the Pillar of Autumn and saying something like "Wake me when we get there...." 

I'm not all that well versed when it comes to Halo mythology...But is it possible that the rookie Spartan you are playing in Reach is the beginning of Master Chief?

Impossible, Master Chief isn't anywhere near Noble Team during the duration of Halo: Reach. ;)

Also, no i don't think you'll play MasterChief for one second in this game, not in Campaign or Multiplayer.

I can imagine him being in the final cutscene/video after credits though.

No its not possible.

But I don't think we will be playing as the Master Chief....we might see him sometime during the campaign though.

No, Master Chief was fighting during the same time and in the game your character can either be Male or Female.

Apparently it already confirmed that both the Master Chief and Cortana appear at some point. Was almost always going to happen, but when and to what degree no one knows (except for Bungie, obviously).

Also theres no chance Noble Six = Master Chief. The Chief has already been in multiple battles as the top Spartan prior to Reach. Noble Six isnt even in the same class as him (ie Spartan III, not Spartan II)

Bungie said the Master Chief will return!

Link: Bungie Makes A Killer Announcement Regarding The Master Chief

So I'm going to go with a yes.

Hmmmm interesting....