The talent build I've been happy with on Beta is Soul Fire, Internal Combustion, Grim of Sup, Soul Conduit.
The extra button from SF and the extra Immolate oversight from IC add enough moment to moment complexity to the rotation to keep me entertained. The extra resource generation from SF and SC means I can reliably Conflag into a Backdrafted Chaos Bolt nearly every time. There's a satisfying rhythm of a few Incinerates, throw Soul Fire as it comes off cooldown, refresh Immo, Conflag, Backdrafted Chaos Bolt, repeat.
More active buttons like Shadowburn or CDF feels crowded. More passive choices like Reverse Entropy feels boring and unsatisfying. This build hits the happy Little Bear spot for me, and I hope the tuning passes make it a viable one.
ETA: I think the key to Internal Combustion is that you stop thinking of Immolate as a DoT to refresh in the right window and start thinking of it as a resource meter to refill either when it's running low or when you need to top it off before a burst phase. Those extra Immo casts are sort of taking the place of Life Tap as a decaying resource you need to refill regularly. And with SS flowing so freely the extra check of "Do I have enough Immo charge?" before casting Chaos Bolt isn't particularly heavy, once you get used to it.