I've done some more (mostly random) work on the code, and I've decided that I should completely decouple some parts (like DoTs) to write them as "general code" calling some DoT-specific logic at times.
Then 5.2 arrived and messed up the parsing.....
Blizzard seems to have added 6 fields (one GUID + 5 integers) at random in combat log events. I say 'at random' because even if the placement is constant, the presence is not. Monk HoT ticks have this additional information, Druid HoT ticks don't. Looking at the data it *could* be that the data is about the spell/event target and the 5-digit numbers make me guess current HP/mana, but I have no idea what the additional 3 values may be, and even less I can guess why only some events have it.... (maybe it's a "work in progress" and they have not yet updated all spells to support it?).
I have fixed the parser to be able to deal with the new logs, but I'm waiting to see if I can get some solid information on those numbers to see if there's anything exploitable for health (or energy) tracking.
UPDATE: ok, my random guess is as good as anyone's after playing with SPELL_CAST_SUCCESS:
Caster GUID, Caster HP, Caster Mana, unknown, Power Type, Power Amount *after the cast*
If it's true then health/energy tracking has become a whole lot easier!
UPDATE 2: thanks to the guys at WoL, the values are:
3: Attack power
4: Spell power
5: Resource type
6: Resource amount