I figure we're almost exactly 24 hours from the expected announcement of the first Cosmic Encounter expansion — see post below — so here's a quick guess at what we'll be seeing:
Title: Cosmic Encounter: Incursion.
Size: No more than half the size of the big CE box. Thinner, like one of the Lords of the Rings expansions.
New aliens: 20 to 25.
New mechanics: Hazards is a definite, as its already mentioned in the original CE rulebook. Rules and pieces for a sixth player will be added. I also expect to see one totally new mechanic (much like Tech was completely new in the original edition).
Price: Either $29 or $39, depending on how much of the new stuff is printed on heavy stock.