So far most of this homebrew has been pretty "broad". Anyone doing anything for specific classes? Most felt pretty good by the end of 4e, though Psionics could have used some more support I feel. I want to write up some sort of Feat to help out the Battlemind's "Mind Spike" but really can't come up with anything besides giving it range.
I've been in 'road warrior' mode all week, so I haven't had a lot of time to dig into specifics. In HoML each class has a damage die and weapon/implement proficiencies. Weapons and implements each have a small damage bonus (so a dagger does SLIGHTLY less damage than a great sword, like 2 points vs the 4 point difference in 4e). This establishes your basic role-based damage differential. There are class boons that provide for damage kickers for strikers, added stickiness for the knight, some control riders for controllers, and of course some buffing features for leaders.
You can pick any or all of your class's starting boons, usually there are 3, but a class could have more. IIRC knights have a 'use my shield to absorb some damage and it becomes broken' a 'get extra OAs', a 'mark and punish', and a damage bonus with large weapons. Depending on which ones you pick, you'd be stickier and/or more punishing, closer to a striker, or operating in a more defensive damage soaking mode.
Rogues have boons close to their 4e cousins. There's a 'sneak attack' bonus to damage, a first strike bonus, and a 'get back your Vitality Point if you used it as an extra action and got a Complete Success' feature (so basically a free AP if you roll well enough). That gives you a quick and deadly combatant, though the details vary slightly from 4e (really its mostly just cleaner and missing some of the arbitrary flavor restrictions). There's also a 'Thief' boon, a 'Trickster' boon, and a couple others that generally work well for different sorts of rogues (but could be applied to other classes as well).
Priests are pretty much the 'Laser Cleric' half of the 4e Cleric class. The other half is relegated to paladin, so there's a nicer distinction than in 4e or D&D generally (Priests cast spells, paladins hit things). Some priests can be reasonably competent melee combatants however. Their features are fairly close to 4e, but tied more closely to their choice of god(s). Any priest can pick the 'be a decent healer' option, some can pick super healer, others can pick various buffing/debuffing options, various flavors of 'turning', etc.
Beast Master is a fun one, but I'm still working out some of the details on that and hasn't really been tested at all. Again, its not radically different from the 4e ranger option (and don't get on me about how that was weak, it wasn't).
I'll try to post some real specifics soon, though you're all welcome to peruse the PDF I linked in my OP. None of the classes is really fleshed out much beyond the first couple of levels, as there simply aren't enough boons defined yet for that, particularly items.
