I've decided to start a petition for a Pride of Nations sequel. What motivated me? A post by one of the developers on the AGEod forums, found in this thread: http://www.ageod-forum.com/viewtopic.php?t=54094
Here's the quote, from Pocus:
"I can certainly redo it in Archon (the engine used in Empires). We just need 2000 players lobbying Slitherine that it's a good idea

So by my count, we only need 1,999 more letters to get a sequel to the greatest simulation of Victorian era warfare, along with its wonderful management layer. Let's do it!