If the only opportunities for advancement in your organisation beyond "senior developer" require a move into mgmt or team leadership, that will work against the stability of your teams. Seriously consider hands-on dev career paths with equivalent status and rewards.
I see no real reason why a developer can't reach CTO-level status (and pay) within an organisation, while continuing to work where they offer the most value: mentoring and setting an example for teams.
If you believe promoting them into management roles is a way to retain your best developers... well, you haven't retained your best developers, have you?
@jasongorman Peter Principle at its finest.
Also it's the reason why I went out on my own in 2005.