Certainly not manually, but automatically. This does require some type of "if/then" logic in your router (ie, if you don't see this route from this source, then announce these routes to xxx). If your router can't do this, then you need to talk to your router vendor*. One needs to define quickly, but the time it takes to propogate a route isn't that long. * - tell them they need to do things like this and build a router that will handle several 100k routes.
There is no question that more people are needing more reliable connections to the net. With some education, tools, and the right pricing models, people can be encouraged to get backup connectivity in a manner that doesn't impact the size of the routing table. Specifically, they should not announce any routes on their backup connection unless their primary is down. ISPs should provide
Is there some trick here or are you saying that a duel homed ISP should manually update their announcements when their primay pipe is down? I think that, in theory, your statement makes sense, but I don't know how one accomplishes it in practice. Outbound traffic is easy, but if one is duel homed and wishes to have inbound traffic find their network "quickly" and dynamically when their primary pipe is down, I believe it is necessary to advertise ones routes via ones backup at all times.
Jim