DreamHost do backup your MySQL databases, but I don’t think you can actually download these backups. However, you can restore your database from one of the previous backups via the panel;
Goodies -> Manage MySQL
Then click the small RESTORE button next to the relevant database. You can now select which backup you wish to restore from.
Save [color=#CC0000]$50[/color] on DreamHost hosting using promo code [color=#CC0000]SAVEMONEY[/color] ( Click for promo code details )