Every company has it's own culture, and with that, most companies have a position level that represents "rarefied air" within its culture.  The rarefied air, in your company, is the position level that, once you are promoted to, means you have officially arrived and are considered a true player within the organization.

For some companies, that means a Director-Level position.  At other companies, it's a VP slot.  As Jason Pankow and I have written in the past, there's a lot of title inflation going on out there, so you can't use titles for anything involving comparison across companies - too much variability.

But, they do mean something significant within your company, and that's the whole point.  Jessica Lee of FOT fame has thrown up her own blog (Jessica Lee Writes), and in an early post, has posted a gem identifying the "rarefied air" that is a senior level designation at Microsoft.  At the anonymous blog Mini-Microsoft, the topic of getting promoted to level 63 (a senior level within the Microsoft group) is broken down. 

Mini-Microsoft waxes on what a Microsoft employee needs to get to a level 63, when you're a Redmond PC:

"-They can own a room: they aren't warming a seat but rather can take charge of a conversation and represent such a deep level of knowledge that they gain respect for what they say and earn a good reputation. Their focus stays on accountable results and this person can bring resolution and closure together.

-Expert: They are sought after to be in meetings, for instance, so that good decisions can be made.

-Makes others great: the team benefits and grows from the person's contributions. Answers questions from the team, from support, from customers. Knows what the team delivers backwards and forwards. They are a good mentor.

-Influence when they can, scare when they must: they have fundamental skills in influencing people, but if they need to flip into junk-yard dog mode, they can. They don't give up and walk away but rather fight when they need to fight, escalating only when needed and with lots of justification.

-Makes the boss great: if the team and your boss are succeeding because of you, of course you'll be succeeding too.