We will probably be implementing all 1.8 features. If things play out badly or the general community do not wish to have them then some may be removed.
If that is the case, we may want to consider running the new 1.8 map with nothing transferred over for testing purposes. Once we think we are happy with it, then we can start the move. I worry that if we decide we don’t like a feature, that a restart of the map would be necessary.
I’m sure Andy will consider the risks, right Andy? 
We’ll have to play Vanilla Minecraft for a while until Bukkit is released anyhow and judging by how the time taken with the bug list previously I’m sure it would be weeks before we’d get a release. That’ll give us plenty of time to test
From Jeb’s twitter:
@_ganzi_ Aha, I interpreted the question as if the *current* kind of survival mode will remain, and it wont since we're changing it now
So yeah. Survival, as it is now, will not remain.
notch Markus Persson 1.8 is not done, we need to tweak a few things based off feedback at PAXYAY
notch Markus Persson Today I cleaned up sprinting (it's infinite now, but drains lots of food. Jumping is boosted) and added the player list in multiplayer.
Jeb just posted the new terrain.png and items.png
beside the cracks (bottom of terrain/png, what is that! :o
i can see something that looks like a dead plant, and the melon and melon slice
Apperently the new explosion graphics are a shockwave rather than smoke.
I also see ivy, iron bars, rotten flesh, 2 new seed things
And new half steps? Also, stalagmites.
Not to be a grammer nazi, but stalagmites are on the ones that go from the bottom, stalagtites are the ones that hang from the top of caves 
Well if they added everything at once, it would be so hard to find any bugs in the new blocks. Minecraft could be broke for who knows how long, like it was with 1.6. I don’t mind it comming out it two updates either. Gives me more play time.
They said they were everything at PAX, and at PAX in creative mode they had 3 or so new half steps Liam
The new pig model will have snouts, sorry i could not post a pic this was typed from my phone
It is the new open chest models that were rumoured from a leaked image during his livestream earlier
Edit: Oh it seems that chests are now probably entities that randomly spawn in deserts. Someone noticed something in the picture and zoomed in on it:
you would need eagle eyesight to see that…