They were planning to join maps together on PC so there would be fewer transitions, but obviously ran out of time leading up to Christmas. Actually, this is a lie that Warren Spector told in an effort not to alienate his PC fanbase, but it was always and ever a bald faced lie.
Chris Carolco, one of the programmers on DX : IW came onto Ion's own DX2 boards just after the game was released to address that argument, and said that they
NEVER planned to have "two versions of the real estate" since it would be "a logistical nightmare".
Hence, Warren Spector lied, or just didn't know what the fuck was going on with the development of the game, in which case he should have kept his yap shut about it.
Oh well, Ex Deus didn't sell for the Xbox either according to several magazines' sales lists that I browsed through the other day, so it's very unlikely we'll ever see another sequel. One franchise killed.
And I have full confidence now that after the release of Thief : DumbAssName, Ion will be batting 2 for 2 in that selfsame category.
Creston
Edit :
I remember I would get so disconnected from reality that even though I knew I was looking at a computer monitor, I would try to peer around the edges to try and see around the corners in the game 
I'm glad I'm not the only one who does that. First time I ever did it was in Doom. In my opinion it's just a sign of a very well executed game if it gets you to do that.
This comment was edited on Jan 23, 09:31.