Early playtesting seems to indicate an unnecessary amount of acceleration. Considering dropping some land and adding some or (probably not) all of Thraben Doomsayer, Silverblade Paladin, or Angel of Glory's Rise, because I actually have those cards. Sure, more of either of the two mythics would be sweet, but... Haven't played it extensively yet, so I'm not 100% certain that it's too much, but seems like it at the moment.
I find my U/R Delver deck to be woefully unprepared for this. Sunpetal Grove can be 4x at most. It's a impressive deck list and usually dropped a turn five win con.
I'm not excited that wizards has and is going to nerf counter spells... there goes blue's only answer. Playing this deck, the printing of Cavern of Souls, hearing that Mana Leak is "too powerful" and my experience with hexproof ramp decks makes me think that blue is utterly unplayable.
Unless blue gets a mechanic saying, "all creatures lose hexproof until end of turn" and/or "unpair all soulbound creatures", blue is finished for the foreseeable future.
I'm also not convinced of the necessity of Descendants' Path. It's a nice idea in theory, but unless I get Angel of Jubilation out on turn 3, have Descendants' Path in my hand and NO other mana-producing cards, it's pretty much a moot point.
Here's the adjustments I'd make:
Tossups: I'm not sure I like birds here now. I also don't really like the card:Angel of Glory's Rise; it does do something good but it's more of a sideboard card.
Something to Consider: I think you desperately need some tempo; to that end I suggest Abundant Growth . It mana fixes and let's you draw a card. A couple of Ground Seal s main board or at least side board would also help in certain matchups.
Deck is current as of 8/10/12. Tied for 1st that day at FAM. The only things I would say to your suggestions, since some of them were based on outdated info, and some of them I took, is that A) you can't make me drop below 2 Increasing Savagery , B) I will drop all the birds as soon as I get a 4th Cavern of Souls or it rotates, whichever comes first, at which point I will add some combination of Champion of the Parish , Silverblade Paladin , Sublime Archangel , Hero of Bladehold , Thraben Doomsayer , or maybe even a third Ajani, Caller of the Pride (I like him). Which leads me to C) Thraben Doomsayer effectively won me several games that day, as it both stalls and pumps theoretically six but realistically at least two of my creatures. It's been an absolute champion thus far, and I would/will strongly consider adding another. Oh, and I guess D) I know card:Angel of Glory's Rise SHOULD be a sideboard card, but I haven't been able to move it out since that dramatic win I had with it at my first FNM. But I know. The way I keep rationalizing it though is that I either need it, in which case sweet, especially if I can keep a Champion on the field before I drop it, or I don't need it, which is either as a result of being about to win (good) or being about to hopelessly lose (bad), in which case none of the things I would be adding in its place are going to change the situation any more than it is. And Ground Seal will definitely be going in the sideboard when I get one.