The Terran player (of course) went mech to show off Warhounds. A
The Protoss player did some annoying Oracle harassment--I still think Oracles are stupid--but he didn't commit to it. That was the theme for the Protoss player; he didn't commit to anything. He made some Tempests but he didn't commit to air supremacy against a Terran with little to no antiair by adding Void Rays or a Mothership. He had the Mothership Core up early, but he never made it into the Mothership proper. He made basic gateway units, but he couldn't commit to that, either, because of the supply taken up by the Tempests. I think dedicated Protoss air compositions can be very strong in HotS, but there's probably huge timing windows for the opponent to exploit with that style.
I'm still a little concerned about Terran lategame--does PDD work against Tempests and Locusts? But other than that, Terran seems quite good. Mech seems like it will be viable in all three matchups, which may make the bio threat even bigger. As for Protoss, they have some earlyish harass with the Oracle, but in both Battle Reports, it didn't seem to be that effective. The "Stephano style" Zerg is probably even stronger with Swarm Host transitions, in addition to the Infestor and Spire transitions, but Protoss still seems highly susceptible to it. I'm looking for Protoss players to skimp on Gateways early on in favor of double Stargate harassment.
I'm still looking forward to HotS, and I'm still probably going to buy it. It's still too early to discuss balance--wait for the beta proper to be released so the pros can seriously dig in before even thinking about balance. Not that that is going to stop anybody from whining about HotS balance...