I like new science packs. They're thematic, they have a theme to them.
But old science 1/2/3 packs look bland and uninteresting compared to new ones.
So the suggestion is to replace them with a selection of thematic science packs. Or at least to rename them appropriately.
1. Red Science Packs could be replaced with Engineering Packs. Which would coincidentally need a gear and a copper plate.
2. Green Science Packs could be replaced with Logistics Packs. A belt and an inserter feel like a logical recipe for them.
3. Blue Science Packs could be replaced with either Electronics or Chemical Packs. They would need a recipe change to fit the theme though.
Now, a more daring solution. If research themes are introduced, the next logical step is to introduce thematic research packs of varying levels. So you would have Basic Engineering, Intermediate Engineering and Advanced Engineering Packs. Higher-level recipes would then put requisites not only on science pack types, but on their levels as well. So you could have a research which requires Advanced Chemistry Packs and Basic Engineering ones.
Naturally, player would be able to use higher-level packs in place of lower levels, with appropriate improvement of performance - similar in a way to how fuel energy works. So when using Advanced Engineering Packs to research a tech with lower requirements, each advanced pack would provide the equivalent of 2 intermediate or 4 basic packs. Shouldn't work the other way though. Essentially, this allows the player to completely replace his science pack production lines with more advanced ones and scrap lower levels entirely - at the cost of some resource efficiency when researching techs with low requirements.
More importantly, introduction of science pack levels would allow to reduce the number of science pack basic types while retaining (or even increasing) overall complexity. Production Packs are a natural fit for Advanced Engineering, and High Tech for Advanced Electronics. The entire science setup would then contain the following lines:
Engineering Packs - related to production and automation (and possibly power production as well).
Logistic Packs - all things related to transportation: belts, rails, logistic networks, engines, cars...
Electronic Packs - related to all things high-tech. Mostly supplemental for other research.
Chemical Packs - from basic chemistry to nuclear. Or skip them.
Military Packs - everything that does bang.
Not sure about Space Science - it's obviously a way to make rocket launching worthwhile, but there are no techs in the game where space science requirements would make sense - except rocket research which you need as a prerequisite for getting space science. Kind of illogical IMHO. Perhaps launched rockets could replace the Lab Effectiveness tech branch and increase lab productivity directly, instead of producing science packs. And maybe that boost could be temporary, to stimulate players into launching more rockets.
So that's it.
Note: I'm aware this is guaranteed not to be implemented for 1.0, with the feature freeze and all. But still something to consider.