Looks like DreamHost is launching a new pricing structure together with their birthday promo.
There is currently only 1 service plan (which includes 500 GB disk storage and 5 TB monthly bandwidth) and a number of new add-on options:
Premium Phone Support ($9.95/month)
Double to 1 TB Disk Storage ($9.95/month)
Double to 10 TB Bandwidth ($9.95/month)
VPN Access ($19.95/month)
So goodbye [...]