Doom Blade kills Titan, Wurmcoil, and Nexus. Also, Valakut didn't run any Wurmcoils, and only ran Avenger half the time.
I like the Solar Flare list, although in testing it is ridiculously hard to get the mana for a turn 3/4 Liliana, so you might want to cut one. Your manabase seems a bit dual-heavy. 12 M10 duals with only 8 basics? I'd run 6 Scars duals, 9-10 M10 duals, and 10 basics. You might want another Sun Titan in there, he's pretty ridiculous.
As for the sideboard, dedicate as much as half to Tempered Steel. I've been testing the deck, and even with 3 Days, 3 Timely's, a Wurmcoil Engine, 2 Doom Blades, 2 O-Rings and 2 Gideons (along with some artifact hate - I think it was Revoke) they get destroyed. My testing looked something like this:
2-1 Tempered Steel
2-0 Tempered Steel
2-1 Tempered Steel
2-1 Solar Flare
2-0 Tempered Steel
Steel went 4-1 (9-4), boarding out Dismember and Vault Skirge for O-Ring and Shrine.
But back to the Wolf Run topic - this weekend, Wolf Run took 4 out of 8 spots in the Top 8 for GP something-or-other. But people will adapt, and it will probably do something similar to Mono-Red (amazing results, and then dropped off). If not, I might consider moving to EDH until Primeval Titan rotates. I have a very deep hatred for decks like these, and if this stays big I will dedicate almost my entire sideboard to fighting it (I'm testing the matchup against Tempered Steel tomorrow).