It feels like Gen Con usually has a warping effect of FFG's releases, which I guess is understandable. I'd assume they'll have some early arkham products at their booth in addition to the Blob scenario. This seems like a good guess since it was targeted for the same time frame for release. The other obvious choice would be Dream Eaters, but it feels real early for Dream Eaters. That said Dream Eaters would be an easier product for people to enjoy at the con. I would imagine a small subset of arkham players will be bringing Carcosa scenarios with them to the con.
The more I look at that upgraded .32 the more I like having a small gun that you can pop in and out of your hand. With Well Prepared on the board it's pretty much all you need for a whole scenario. Maybe not as flashy as spending that 4 xp on the BAR, but still it feels like a cool build. That said the BAR is also a nice gun for Well Prepared.