Nope.., it's a budget rompler. It's the lowest model in the Juno line up so no expansion on this model (not surprising either as both Yammie's and Korgs budget workstations have no expansion either).

It's def a major step up from the current Juno D model.., but leaves enough room between it and the next step up (which is the Juno G). Here's an online price already listed for the UK.
http://www.dolphinmusic.co.uk/product/41224-roland-juno-di.html

They price they have listed there is 549..., quick estimate on the conversion rate I'd say that's just under $770 US.