Their dashboard is completely custom and not cluttered like other systems like cPanel. Their navigation makes sense and generally allows easy customization for whatever I need with my shared hosting plan.
You can enable specific IP(s) to connect directly with your (shared) MySQL database server. This is very useful for external applications and/or using your own database administration utility; large backups or restores, etc.
You're allowed UNLIMITED sub-domains on any of your hosted domains. This is very useful for logical segmentation of your web application. Or binding a sub-domain like 'svn.yourdomain.com' to a freely hosted subversion repository. Which, is another great feature for anyone wanting their own private revision control system.
Cron jobs are fully supported. Fair warning: it requires a little knowledge with Linux file system, being that everything is hosted in a Linux environment. It's not that difficult to figure out once you have something up and running.
However, if you're getting nowhere fast, they do have a decent and somewhat consistently updated wiki that gives you basic instructions on how to setup virtually anything in your account.
There is also a decent status dashboard page you can use to monitor degraded services or subscribe to their twitter support account for updates.
Whenever you setup a database host name, they force an instance of phpMyAdmin to load if a connection is established on port 80[/443]. This may be desirable for some novice users, but I see it as a serious security risk. This basically invites hackers to attempt a brute force attack on the ENTIRE shared MySQL database server(s).
Sometimes settings are not fully applied to your account if you're making rapid changes to similar services. This may require hitting Save on some settings, again. This can be a pain when you're not sure if the changes not taking affect are because of a misconfiguration on your part or because of the aforementioned.
Despite being on a shared hosting plan, service can still be somewhat slow. Response times are pretty quick, but overall system resources on the server processing any of my PHP scripts seems constantly taxed. So, it would seem that their could be more policing of other users that may be abusing shared resources.
Don't expect Amazon grade web services from Dreamhost. They're a decent web hosting provider, but if you're designing something to continuously scale, I don't feel Dreamhost would be right for you.