Yes, you can connect other services!
Mobile services are mobile applications. That's why they are under the Mobile heading in Bluemix, but many other services include their own mobile SDKs.
For example, here is a link to the Watson Developer Cloud Mobile SDK, where you can add Watson services to your application:
Here's a quick overview of the Bluemix Mobile services that I posted as an answer to another question.
Here are the current services that we have, and some information about them that follow the MBaaS pattern, as well as some links to get started):
Mobile Client Access
. Facebook, Google .
Push-
Push- push- Android iOS.
(-)
Mobile Analytics , .
Cloudant NoSQL DB
Cloudant - IBM NoSQL .
- , , .
Mobile Foundation, . .