I would hate 10 levels at MoP rates, I hate leveling and when you have multiple characters to get to max level it becomes a pain.
In regards to the lvl 100 thing, Back in Vanilla there was a blue post that stated "We don't want levels to get super high and see 100 as being a pretty good spot". Of course things have changed since then and I don't think that will be the case anymore, but what people are saying was at one time valid.