Since you have stated before it is your work on business systems that provides the money for your company, and the work on the games is icing on the cake I will assume that the impact on your bottom line in dealying a release until 2008 is not a significant concern (or at least one that as a CEO you are willing to account for).
I will also take the fact that you asked the question of us at face value and assume that our answers actually do mean something to you. (That it is easy to believe based on the concern you have shown in the past for your customers, makes that an easy one.)
Waiting will give you and us:
1) Solid individual AI's
2) More time for feature requests
3) Less opportunity for major bugs to impact consumers not familiar with Stardock's customer support.
4) More opportunity for good press. An important point as this is what will bring added name recognition to the public unfamiliar with your work, this will increase long term sales more than a Christmas release of a less superior game.
5) More time for the members of the modding community to have major mods ready to go on release.
Not waiting will allow you:
1) To have additional sales in a holiday shopping period already expected to be sluggish.
2) To Compete with all the other new games for copy space in magazines/web sites, retail shelf space, and for the attention of the general game buying public.
3) To appease the part of your fan base that does not want to preorder and take part in the beta.
4) To give you that sense of peace and satisfaction Christmas morning (or Kwanza morning of Chanukah evenings or even boxing day morning if you prefer

) that you are "finished" and that you released two expansion packs in 2007.
even if it means having cheated your fans out of the AI they could have had... that they deserve... Â

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5) To Know that you didn't let the terrorists win. (or some other vague post 9/11 reference)
Oh and almost forgot to mention that waiting will allow Carielf more time to read all the flirtatious emails she undoubtably gets... now wether that is a good or bad thing is up to you to decide.