A: When it's an 8" tablet.
Rounding to the nearest integer makes a lot of sense to me. Rounding up is also pretty common (My 32" TV has a 31.5" panel, for example).
I wouldn't call a 7.85" tablet a 7" tablet (it would be noticeably larger), just as I don't call my phone's 4.65" screen a 4" screen.
That blog entry is also trying to emphasize the fact that it's a tablet class device and not one that's comparable to a phone sized handheld, so it makes sense that they've picked rounding up (it also makes sense because it is mathematically more accurate).
If I was going to pick something in that article to complain about, it would definitely be the rumored 1024x768 resolution. 4:3 and low res for an 8" (or 7") screen is a lackluster resolution after all the touted benefits of "retina" displays and the competing sized devices that are at least 720p.
Anyways, rounding to the nearest whole number makes a lot of sense to me, it's what I was taught was rounding (unless to 5s, 10s, etc) in elementary school.