RDW projected out past rotation...no Stromkirk Noble, no Lightning Mauler, no Pyreheart Wolf, no Vexing Devil, and no Hellrider! So...no chance?
...well, not so fast. Can Red Deck (still) Win without those toys?
Let's see here. We lose a little speed, obviously, with Vexing Devil and Stormkirk Noble vacating the one-slot. The only new one-drop is Striking Sliver, but unles you build up other Slivers around him (which changes the deck pretty dramatically), he's just not really worth it, in my opinion. So instead, let's shove Shocks in there to just burn out early opposing threats. (Searing Spear remains for now, because I imagine there will be SOME 3-damage spell for 1 or 2 CMC in Theros to swap into its place.)
In the two-slot, we gain Young Pyromancer. He's not speedy, and he doesn't drastically aid in the fight himself, but he DOES potentially boost our overall army quickly as we cast burn spells, and he's a 2/1, so worst case he's still a decent scrapper for the cost (and other way to make use of the RG that comes from a preceding Burning-Tree Emissary).
Probably our biggest gain is our direct Hellrider replacement: Ogre Battledriver. Exact same cost, exact same stats, but a rather different ability. Again, we trade speed for other benefits (no haste), but he starts paying off immediately after hitting the table by giving all OTHER creatures haste and a nice attack boost as well. Just as Hellrider could turn late-game weenies into at least a little guarateed damage, the Battledriver can turn a late Cackler or Pyromancer into a major short-term threat as well.
My particular build has some combat tricks, which are usually very unexpected for a deck like this and can be powerful for that very reason. Would would expect a Rubblebelt Maaka to turn first striking Ash Zealot into a real killer, or to make Boros Reckoner even more of a pain when the opponent finally gives in and thinks they're going 2-for-1 just to get rid of him, only to end up on the wrong side of a 2-for-0 instead? And Weapon Surge really should be played more. It is just sick against opposing aggro, giving your team first strike and a small boost and rip the opponent's army apart if played at the right time.
Other M14 additions that can help are in the sideboard (for now, at least). Mindsparker is not only is it a 3-power first striker for 3 mana, but it's got some great anti-control damage potential. Seismic Stomp can lead to a very quick victory against an opponent low on flyers. And Burning Earth is nice if you find yourself facing one of those heavy-control, three-or-more-color decks that like to try and abuse aggro.
Yes, this is still fragile to sweeps or lots of targeted removal, and it's a hair slower than the glory days of RDW, but I think it can still pack some serious punch. How about you?