And you'll need to earn the right to play it.

I think this is a really cool. Basically you'll get to play out the events that take place between the time Marcus Fenix sends Cole and Baird to get supplies and the final battle of Gears 3. There's no clear talk on how you unlock it yet but they did mention that you would need to get stars during the campaign to unlock it. Looking at the achievements it seems like there are at least 100 stars to get:

revisiting shadow moses in pure mgs 1 fashion in mgs 4 comes to mind.

Fucking yes! That sounds great; pleasantly surprised that this'll actually be an in-game unlockable and not DLC too.

I was having that dream again...

and then you can play the game with the ps1 snake head model from mgs1

mannn with this drought of games till gears and bioshock infinite (nothing releasing this week has interest to me) im gonna replay mgs 4 again, i think that game is getting too much rearview hate now.

As for games that have you return to environments from previous games, returning to the Ishimura in Dead Space 2 is possibly the greatest segment across the franchise. Rebecca Chambers during RE0 somehow finding herself travelling through the factory that'll take Leon/Claire down to the Umbrella Laboratory in RE2 was really cool, too.

And of course, as already mentioned, the flashback to MGS1-era Shadow Moses in MGS4 was incredible.

A yes...damn I nearly forgot all about that segment, such an awesome highlight of Dead Space 2.

Awesome. Man, Judgment seems like really, really cool.

I really like the bit in Dead Space 2 where you revisit the Ishimura.

Indeed! I actually only played the game for the first time... well, I guess it was over a year ago now, but it was relatively recently. I wrote about it- you know, the two times I blogged before deciding blogging wasn't for me. But yeah, listening to the bombcast last week and hearing Brad say he couldn't remember what made that game great had me shouting at the radio. That's pretty much because the spolier Snakecast and GOTY 2008 battle where Brad was FIERCELY arguing for Metal Gear was pretty fresh in my mind. I'd play it again, but I'm playing Revengance right now... and I want to play Tomb Raider.