Hi,
We have a blog that provides details of updates to Creative Cloud http://blogs.adobe.com/creativecloudenterpriseupdates/
Additionally if you have built packages on the dashboard they will note if they require updating, i.e. if a new update is available. Also the same feature can be seen within CCP itself.
That said, I agree that this would be a great feature to see more directly on the dashboard. It is a frequent customer request and the product team are aware of it so I hope to see it sometime soon.