simon asked: "Do all package maintainers have write access to their respective packages?"
Not automatically. Without an current, updated list of maintainers there's no way for the gatekeepers to keep CVS write privs updated. so patches are the way to go for the time being.
If you are a package maintainer, you can email the gatekeepers for access.
disclaimer: i am not a gatekeeper, but i do admin the cvs tree from time to time.