The secret url link which saves your bitcoin is never a good idea. First you can easily lose it and second, its very easy for a hacker to look at your cache and try to access it without your permission.
It was a smart move for the SatoshiDice guys to move into a user/password authentication system, I was never confident investing in the site with that link - Not sure how the guys with hunderds of BTC on the bankroll slept at night. Will be even better when they have 2FA enabled as well.
the move is definitely good, but loosing balance on old account is pretty annoying
and PM'ing support for 2 month hasnt resolved the issue...