My wife had a medium size bag of peanuts confiscated at one of the trial matches. They seemed to be sticklers early on, but she's managed to get lots of snacks in since, no problem. I've tried some of the food inside, more out of initial curiosity or when running late, but it won't be a regular thing for me at those prices. Bovril (before) or a pint (afterwards) is about my usual limit.
It does feel like a much longer day now though (arrive much earlier and stay much later), and I think that will start to deter quite a few for the less attractive games, the ones in deepest winter weather or night matches. For now, the novelty factor is still there and there seems to be enough non-ST holders or people who still haven't been to take up the resale tickets.... (if the attendance figures are to be believed). Unlike for our neighbours, I don't think that there is a bottomless pit of supporters ready to keep filling the place at current levels of performance. Plus lots of people now talking about no renewing STs in the knowledge that there will be no problem getting tkts on resale. That might have a knock-on effect on hospitality sales as I know a few people only jumped on that option to get past the waiting lists.