I agree that it makes little sense to talk about expansion packs before the game even comes out. That being said, a couple of thoughts:
1) According to Chris Delay of
Introversion Software, content is killer. Their game, Darwinia, was as difficult to get going as it was not because of coding problems, or complexity of the game, or anything like that, but because it had a great deal of content -- different units, a story to be told, different levels, &c. For the big guys, they have a dedicated team of content producers. Most indies, (like IV) do not. Now, IV and Bit-Blot are not the same, and they seem to be content mavens (Alex is a composer, right?), but there is still a certain amount of work that must be done above and beyond the creation of the game to come up with content.
2) I don't think that indy developers are best served by expansion packs. For large companies, they can pump out a new expansion every so often, and people will go and buy it. Indy developers rely upon a reputation for originality to do well. If they create a game, then follow it with several expansions, they may not be seen as original any longer, and lose the support of formerly dedicated fans. There is also a perception that expansion packs are a scheme to quickly and cheaply rake in more cash. Again, this hurts the reputation of an indy developer.
3) To take a different approach, I would love to see a modification scheme. The two software companies that I follow most closely (IV and Ambrosia Software) are both relatively small and independent. They have both built a reputation for originality, and both support the development of plug-ins, add-ons, or mods (whatever you want to call them) for most of their games. This removes from the companies some need to create content, and creates a stronger user community, because there is a reason to get together. This means that they can get to work on their next game more quickly, and that the community will anticipate the next offering with bated (or would "baited" be more appropriate for this community?) breath.
In summary: expansion pack == bad, user made content == good.
xander