Okay so Battle Roads are almost over, I might as well do a little recap.
After Battle Roads, looking at the results alone the tier list would look like this:
Tier 1:
Zekrom/Pachirisu/Shaymin [with Tornadus] (~31 wins)
Reshiram/Typhlosion [or Emboar] (~30 wins)
Tier 1.5:
Stage 1's [lots of combinations] (~18 wins)
Reuniclus/Gothitelle [or Vileplume] (~16 wins)
Yanmega/Magnezone (~14 wins)
Tier 2:
Kingdra/Yanmega/Jirachi (~5 wins)
Vileplume/Yanmega/Mew (~3 wins)
Magneboar (~3 wins)
Tier 2.5 and lower:
Everything else
Really my only big miss was Reshiram, but I still stand by the deck not being that great despite its huge number of wins. I rated Magneboar and Reuniclus, a .5 tier high, and Zekrom and Yanmega/Magnezone a .5 tier low. Stage 1's really is Tier 2 since calling the deck that doesn't do it justice - if the results were accurate enough to divide it between DD, Rush, Weavile, Mew, etc they would all be Tier 2 or worse.
So what will be the play for Regionals? I haven't tested based on these results enough, but I think it's safe to say it will be Zekrom, Reuniclus or Magnezone. These three cards really represent the format now - Zekrom is the best fast deck that beats Magnezone, Magnezone is the powerful deck that beats Reuniclus and Reuniclus is the lock deck that beats Zekrom.
Seeing as Zekrom plays really well in 30 +3, I'd be tempted to say that at first. However, Reuniclus plays much better against most of the other "random" decks that are on the list or managed to sneak in one win. Of course, it auto-loses to random stuff like Blastoise and Mew while Zekrom auto-wins a lot of random stuff like Blastoise and Gengar. Magnezone has more 50-50-ish matchups with the random stuff, so if you're not going to base your decision on playtesting or comfort with a deck, you have to base it on what tables you think you'll be playing at, how much you dislike random auto-loses and how fast you play. Try to tech for Mew if you're playing Gothitelle!
As much as I dislike it, I suppose Reshiram deserves a little bit of a mention. It's a "middle ground" deck. It's not quite powerful enough to beat Reuniclus unless paired with Emboar and/or RDL (or Kingdra lol). It has an okay Zekrom matchup and it does well against some Magnezone variants (Yanmega/Magnezone) while curling up and dying against others (Magneboar). Basically, it's capable of standing up against the fast decks and the power decks, but can't beat the slower lock or power decks.