I gave up on the undocumented extended stored procedures when a service pack broke the one that deletes backup files older than x and every maintenance plan based on the wizard started filling up hard drives. I use an ActiveX script to do tasks like that now. It's not pretty but it's mine and it works. It only breaks when the ActiveX subsystem does, and I hear about that right away.

I also don't like the thinly-veiled threat that the procedures may vanish in a future release of SQL Server. I suppose that is to scare off DBAs that might be rogue enough to call them without summoning the wizard.

It is nearly trivial to write T-SQL for making a transaction log backup of every database that isn't tempdb or set to simple recovery model. I call a stored procedure for those backups from a T-SQL maintenance plan task and it has three advantages over the wizard: 1) It doesn't try to log back up anything in the simple recovery model; 2) It picks up new databases so the maintenance plan does not have to be edited; 3) When the Cowboys in my environment who are too busy to let their DBA know there is a new database in an instance, and it is for x, and it needs to be cared for y, the failed transaction log backup within the next 4 or 6 hours lets me know someone is up to something...assuming the Cowboy isn't aware of the need to make a full backup of a new database (usually a safe assumption)...someone I will have a chat with soon.