My thoughts on the first sneak peak..
First, I'll start with the replay/live replay update. I like it. 'Nuff said.
As far as the walls go.. This will be a little more drawn out. I certainly understand everybody's gripe about walls being upgraded with elixir as well. For some, they're mad that they don't get to benefit from this because they've already maxed their walls, are almost done, or have been sitting on maxed elixir storages for weeks/months.
I understand the frustration, but this is gonna happen with games that are constantly evolving and continually update. This isn't some single player RPG where you finish the campaign and then you're done. Supercell will add more things and tweak what is already there. For the most part, their updates make it easier for the massive number of players that are working their way up to TH10. The players that are already there usually end up feeling gypped because they had to do things the hard way (or spend loads of money). But shouldn't they make it easier for people to reach TH10? Many TH10s compain about the lack of loot, but if they had more players to loot from, wouldn't loot be easier to come by?
This leads to another point, which is the game's economy. Elixir has been very easy to get in this game, as most upgrades cost gold so many players are sitting on full elixir storages once they've completed most of their upgrades. Now that you can upgrade walls with elixir as well, many people think that players will dump all of their elixir into walls and elixir will just vanish from the game. I do believe, that elixir will be less abundant, but not nearly as hard to come by as some people make it out. There will still be players saving up their elixir to upgrade their troops, army camps, etc. There will still be players with maxed storages because they've farmed a lot and their builders are tied up. And there will still be inactive players with loads of loot in their collectors.
The biggest changes that will come from this update will be that more players will have stronger walls, and that players will have to manage their elixir more wisely. We're just going to have to adapt to the changes, or if you can't do that, find a new game to play.
Sorry for the wall of text, just throwing in my 2 cents. Oh, and about upgrading rows of walls.. That's pretty cool too. Just doesn't really help me lol.