In case some people have missed it, Imperial Assault IS Descent 3.0 from both functional and business perspective.
It's clear that Imperial Assault is surfing on the wave of Descent, an already proven game and still very popular. Take the best parts of it, improve the few things that were a bit crappy, and replace the minis by Star Wars collector figures, which every SW addict will be wanting to invest in even if it implies ignoring the rest of the box contents. They target both Descent players to invite them to diversify their gaming experience, and of course all Star Wars afficiodanos. People who really love Descent are likely to invest in Imperial Assault bar the few who dislike the franchise. More money, and a streamlined way to support two major product lines at the same time. They just need to replicate what they are doing currently for Descent. Content shouldn't be a hassle to throw out given the huge story material around the Star Wars license.
A fantastic way to promote a new game is to build upon one that has been working great, dust it off (theme-wise Descent is not a new game really) and put the most awesome franchise in the world on top of it, GenCon package, profit. There will be a huge wave of customers willing to purchase the product.
I don't blame FFG for making this marketing decision.
However, one game has to be inevitably ahead of the other one, and Descent will unfortunaley bite the bullet and become second in priority next to Imperial Assault. Even worse, because of the competition, Descent will lose further attention and lose fans because there is simply a much better alternative to it currently on the market. Think Arkham Horror and Eldritch Horror. Oh I'm sure Descent will still get played in many circles, but we should be able to see a noteable change in the way the product is supported and within the community. Fans may therefore lose interest in a subpar product since all design efforts and support are clearly going to go towards the new game. Want a new LoS mechanism? Look no further, here's Imperial Assault!
You would probably ask yourself why FFG would take the risk for bringing down (or putting in decline, whichever terminology you prefer) one of their flag games. But when you think about it, there is no loss. FFG know well Imperial Assault will get the huge success people are predicting, probably even better than Descent actually, They know that a great % of Descent fans will equally invest into Imperial Assault, building further up the online community for the new game, and that the rather small % of Descent fans who dislike the Star Wars franchise will carry on buying Descent products anyway as they have always done.
But think about Descent now. Sure, you can throw out tiles for every type of landscape there is, all monsters from various mythologies, 57 more elves each with unique bow made of 100 different trees etc. But in terms of skills and mechanisms, don't you feel like we have gone deep already? Not implying that we've reached the bottom of the bag by any means, but don't you think given the latest releases that the quality and creativity has somehow reached a certain level of stagnation? Sure, you can design a new type of Healer and come up with a cool OL card, but isn't it all overlapping in a way in order to preserve game balance? The further you go, the more you affect game balance and the gaming experience in general. Going off with a new mechanism can break a game, as we've seen with BBTM. So following this logic, as the risk grows bigger to introduce flaws to an established game like Descent, can it possibly be a part of the decision that FFG think it would be easier to design content for Imperial Assault than Descent? Or at least start fresh, which probably allows for early mistakes instead of having to integrate a new mechanism to 253 others, plus that said mechanism has to provide something to the game experience?
I know this is all a business, but considering Descent and its current competitors on the market, I find very strange to see this type of decision being made, unless they think the sci-fi title they just announced can compete with its fantasy competitors. Again, the franchise matters a huge deal in the equation.
I guess it is still possible that it won't disrupt Descent as much as I think it will, at least in terms of release frequency and support (although quality may well decrease), but I don't think for a second the fan base will remain intact once Imperial Assault gets released on the market.
And finally, I think it would have been slightly more diplomatic towards the Descent fan base to announce this game BEFORE GenCon, even if it would have implied not revealing its contents before GenCon. They could have gotten their surprise effect in another way than this. Because right now it feels like a "take this right in your face, pal" to every Descent fan expecting news for his favorite game and only being provided with the information that the exact same game is being released by the same company with all the goodies and the "Star Wars awesomeness" combined. Feels tough on us.