I see some 3rd party action starting already. But call me disappointed, as 3rd party sources are often unbalanced and unplaytested. No offense meant to these folks who create the stuff.
Goodman Games has to approve every third party product as far as I know. Balance in a game, which puts so much emphasis on randomness is not really an issue. Some third party publishers have been working on their stuff since the beta version and use them in their own campaigns, thus I think they had enough time and opportunity to playtest their content.
The game is really ripe for:
You can create one in a few minutes and you have plenty of stuff to use for customization. And as others mentioned, we have an awesome Random Esoteric Creature Generator.
Most of the current spells cover more than one. But I do agree, writing spells for DCC RPG requires quite a bit of work.
It's quite easy to write races, especially if you're not going the race-as-class way. My campaign is going to need a lot, and a few of them will be quite extreme.
I was planning to write a few, but changed my mind (at least for now): the already existing classes cover quite a lot. If the PC wants to enhance his class (eg. his warrior wants to be a paladin), then send him on a quest (kill the plague demon of Khazardan and your god gives you the ability to lay hands). I'm going to write some guidelines if I'm going to have some free time, as I promised it months ago.
There are a lot of 3pps working on patrons.
There are already plenty of resources published for both mundane and magical equipment. You don't need the official DCC RPG seal to use them. If you want an exhausting list of equipment, I recommend ...And a 10-Foot Pole.
And levels 10 - 20!
So far reaching level 10 seems to be long and nigh-impossible task. Don't forget, that the levels scale differently here than in D&D. DCC's level 10 is like 3e's level 20.