I've been going 'round and 'round with Google Adwords for years. Each time I change a word in an ad, it has to be reviewed, and the ad team rejects my ad because my site promotes guns. When I explain to them that I don't sell guns or other weapons, and that they have a zillion other advertisers selling scopes and lasers, they realize they screwed up, and my ads run.
If Google Shopping uses the same policy as Google AdWords (which is what they say they're going to do), then my listings should continue, although I'll have to pay for them. If they "modify" the policy to really exclude sites that sell non-weapons, then I'm screwed even more than before Google messed up my rankings, as I get a lot of sales through Google Shopping.
Even if they allow me to continue, it's going to be a pay-to-rank program. You'll have to pay $X just to be in the program, and pay more to rank higher. Then, on top of that, the merchant has to pay for each click. This effectively shuts out the small online retailer.
One possible upside is that if Google doesn't allow listings for scopes or lasers or anything else gun-related, then people looking for that stuff will have to go elsewhere. And maybe that elsewhere will be Bing or Yahoo, where I rank really high for everything.
I hate Google.
