Theoretically, the site will become prestigious enough that in time, it may just get sent review copies (along with associated press embargoes); Until then, it may be a good use of company funds (even if they become loot for other SE sites - you could imagine the tag line -- "win this [compact camera] that the guys over at http://photo.stackexchange.com/https://photo.stackexchange.com/ said was going to revolutionise photography.")
I feel that there would be sufficient interest, both on a readership side and on the authoring side. On the authoring side, and if SE Inc. do purchase the review equipment, I would expect them to have a vetting/auditioning process of their own.
There would be good scope to review other things; maybe regional printing firms for handling gliceé printing. The reviews would sit well amongst articles that could sum up a visit to some of the big trade shows as well.