Not having played the EQ2 Beta at all, I have zero idea what a combat wheel is.
Basically certain skills start a "chain." For instance, any time I land a successful Kick on an opponent, it initializes a chain. Certain skills can link to this chain. In the example of the Kick, I can link to it with a slashing attack, a cleric can link to it with a certain type of their spell, a mage can link to it with a certain type of spell, etc. You know what links by watching the icons that pop up on the screen (though it does take a bit of practice.)
Once a chain is long enough, it initiates a combat wheel. This combat wheel has a certain number of spells or attacks that must be performed. If they are pulled off correctly, the group gets a major bonus - it could be a buff, or a heal, or a damage attack - the effect is dependent on the classes involved and has a bit of a random element with it (with common, uncommon, and rare effects.)
In solo play, you're typically just completing a chain, and that will grant you a bonus effect. The true combat wheel only comes up in group play, and gets more complex (and the chains get longer to even initialize it) the more group members you have.
It takes good timing and good teamwork to successfully pull off the combat wheel. Casting the wrong spell at the wrong time or missing with an offensive spell or attack will break the chain and you have to start from square one again. The combat wheel can literally make the difference in a fight, and I imagine in some boss fights it will be a necessity.
So to answer your original question, sometimes the next spell in the chain or combat wheel might be something as mundane as a "Create Food."
By the way, the spells that make up the chains are typically not that specific. For instance, I can use any Taunt spell to complete my chain, not just the single Taunt. The chain is made up more of spell TYPES rather than specific spells.
Another quick tidbit - scouts play an important role with the combat wheel. In groups, scouts are the only archetype that can actually move the wheel in a different direction to change its outcome.
If it sounds complicated, that's because it is at first! It takes some time to get used to it. The biggest chain I've completed so far is with a 4-person group and it's hard enough. I can't imagine what a 6-person group will be like. It does make combat quite fun though!
[Edited] to correct some information learned tonight. Got a chance to really explore the wheel thoroughly tonight, and it starts to become second nature once you get the hang of it. It still takes a lot of teamwork and coordination, but once you understand the mechanics behind it, it's not that difficult. It's not something you will use in every situation either - for low to equal conning mobs, we'd typically just ignore the wheel, or the warriors would complete their solo wheels. For big fights we'd pay more attention and make sure we pulled them off.
Also a bit better explanation of the wheel's sequence:
Some skill starts the chain - typically just about anyone can link to it.
A second intermediate chain then pops up, usually requiring a more specific chain (a heal spell or an offensive nuke, for instance).
If that's completed the combat wheel pops up. The combat wheel has one or more skills that must be pulled off, but they don't have to be pulled off in any particular order like I first thought. In addition, casting other spells/skills won't break the wheel at this point - once it's up, it's up, until you either complete it or run out of time.
This was in a 4-man group. In a 5-or-6 man group you might have an extra link in the chain, or more skills to be performed once the combat wheel was initialized.
I'm really digging it, it's a lot of fun.