First of all, a big "thank you" for Paradox.
It's very good to see a company that not only gives it's fans(= loyal customers) a chance to give their opinion on something like this, and then respect their opinion.
In my opinion, anything that changes the gameplay should be on expansions only. I'd rather pay more for a more complete expansion than paying just a little and get little. I didn't really like Armageddon, for example.
I wouldn't mind if there were DLC's for the more irrelevant part of the game, ie, eyecandy. Be it sprites, or new music (I really enjoy the music from Paradox's games). But stuff that doesn't change the gameplay.
Also, any content provided as to be top quality.
Paradox's Games are always heavily modded (in fact, I'm not playing the vanilla version of ANY of them). Given that these mods are provided for free, and that there is some very high quality work in many of them, be it gameplay or graphics, if Paradox wants to charge us for the DLC's, their content must be worth it.
Thumbs up for Paradox for caring about their loyal fans/customers.