I use wordpress a lot for work and we always tend to build the site/theme/etc on a dev server and move it to the production server upon completion.
Having the wp blog url stored in the db leaves most of the site links broken until it is updated once the site is moved over. While not incapacitating it is slightly annoying. Recently I had to deal with trying to set up WP on a SSL host (which didnt go well at all), but the url seemed to never work (could have been a server setting redirecting).
What I would propose is storing this variable in the wp-config.php file instead, it seems like it would be easier to update here even if you could not log into the wp-admin (yes I know you can manually do it via the db).