Remember, M12 will be rotating out as well. Delver loses Ponder and Mana Leak, which are huge, as well as Gitaxian Probe. To exist post-rotation, there needs to be another good cheap cantrip, and given the problem's Ponder's caused, I don't see that happening.Though I'm not sure how much the rotating out of the Scars of Mirrodin block will affect Standard, considering the biggest current decks can probably reasonably adapt. For example, sure, Delver decks lose the Swords, but a lot of them already play Runechanter's Pike instead.
No, a Pod deck is a reworked aggro deck with a bit of a midrange plan. (How much depends on the build) Look at the Naya Pod or Zombie Pod decks that've been doing well recently.Birthing Pod is out, but they can be reconfigured into Ramp decks. The duals are gone, but Return to Ravnica is almost certainly going to have lands to replace them with. Venser Control is obviously going to take a major hit, though.
I don't think any of the actual mechanics rotating out will make much of a difference. Some individual cards will, though. Birthing Pod decks are on their way out, though to be fair they can be reconfigured into a Ramp deck--heck, if you don't get a Birthing Pod then a Birthing Pod deck essentially is a weakened Ramp deck.
Last I checked Solar Flare hasn't done well in a while. Even the straight Esper control decks have shifted away from Elesh Norn. Given the weakening/death of Delver, though, there'll be more of a niche for proper control decks to come back in.Other than that, the other major deck types seem like they'll be able to stick around. Sure, Delver might lose the swords, but half of Delver decks are playing Runechanter's Pike instead anyway (I play Runechanter's Pike mainboard and put the Swords in the sideboard). Though I do wonder what Solar Flare will do now that they've lost Elesh Norn. They might turn to Avacyn. It'll really depend on what Return to Ravnica offers.