Sure..but they aren't titled as HL3: Episode One etc. So it would be weird to have HL2, then some expansion-like episodes, and then HL4 :hmph:
I'd say if there is a next bigger HL game, it will be called Half-Life 3.
One thing I didn't get..if Vortigaunts could teleport Gordon and Alyx out of the mess, why did they send Gordon under a pile of junk (where DOG digs you out from) :P
"We're talking forests," says Erik Johnson, engineer and project lead for Valve Software. "We're referecing places like [parts of] Estonia - there are trees, riverbeds, old mines, and eventually, we'll take you to an abandoned missile site"
w00t. my homecountry :imu: