[old-gregg]

Mmm... not really. Dedicated IPs are hard to beat if you have a steady traffic of high quality and low-latency delivery is a priority (think of PagerDuty). Most legit businesses/customers have that. Most likely they're not offering dedicated IPs because they're tough to get, especially if you are a small company in email business.

The reason Mailgun and Mandrill can do this is because they belong to much larger companies with better access to IPv4 stockpiles: Rackspace and Mailchimp.

Source: I worked at Mailgun.