Rugrats co-creator Paul Germain (who was actively involved with the first three seasons before leaving to work for Disney) has admitted that he was not a fan of the idea of a spin-off where the babies are all grown up because he thought it wouldn't make any sense as the original series was about babies who don't understand the world.
The last of the original three Nicktoons to get its own spinoff (Doug-Disney's Doug; Ren & Stimpy-SPIKE TV's Ren & Stimpy; Rugrats-All Grown Up). Additionally, the first Nicktoon spinoff to actually air on Nickelodeon (not counting Action League Now, which was just repackaged segments from Kablam).
There is a "Rugrats" special called "All Growed Up" which is a pilot to the spin-off.
In "Truth and Consequences," Dil is the only one to not turn on Tommy.
Kimi and Chuckie are similar enough ages to be in the same school classes, a year above Tommy, Lil & Phil