My PPM and PMO presentations include a slide that depicts the project initiation spaghetti between IT and the business and a following slide replacing the spaghetti with a single arrow (representative of the formal work initiation process you describe). Many folks wince at the graphic but I quickly address their concerns about bureaucracy and bottleneck by pointing out the single-arrow is conceptual. An organization may deem it appropriate to establish and manage multiple formal work-request channels – optimized to specific request types. The single-arrow is used to represent the aggregate, pragmatic, formal management of project work requests.

I don’t care if it is one request channel or a dozen, as long as it is formal: appropriately designed, thoughtfully and thoroughly implemented, and diligently managed.

Steve Romero, IT Governance Evangelist
http://community.ca.com/blogs/theitgovernanceevangelist/

It’s funny, I’m one of those people who’s impatient with a lot of Agile things because they’re too structured (!) but you really do need a scope, even if it’s “keep working through the card deck until you’re out of money.” And a customer, even if it’s yourself. And an ROI, even if it’s acknowledged that the return is purely speculative or perhaps just fun.

You have to know what the project is, who wants it done, and why it matters. At the very least. No matter how flexible and crazy your development process is supposed to be!