They're just numbers. We don't think it starts getting scary until the human mind literally has trouble processing the digits. If your new staff has 152,420 spell power, well, yeah that's a mouthful. But if your new staff has 4000 spell power, the only thing that can really be freaking you out is that 4000 is just a really big number compared to the 100 spell power you might be used to. Automobiles used to cost hundreds of dollars instead of tens of thousands of dollars too.... Smiley
When players say we had scaling problems in Lich King, what they mean (or at least what they *should* mean) is that we picked the end numbers we wanted for percentages such as crit and dodge and then picked ratings that would get us there. When we inflated the item levels to account for hard modes (with a little help from things like glyphs too) then the percentages ended up higher than we intended. That doesn't mean that exponential scaling on gear is bad. It just means that we misjudged our endpoints.
Gear inflation is just part of MMOs, or at least the kind of MMO that we make. Players are going to freak when they see the Cataclysm gear (because believe me, we did), but it's also exciting too.