The OpenGeo Suite 4.0 has some issues with dependencies specifically with respect to GDAL and PostGres libraries.
The issue arises when one tries to install libgdal-dev, which is required, among other thingds, to get ECW reading working.
I tried installing the OpenGeo Suite 4.0 on a fresh install of Ubuntu Server 12.04, and also tried an upgrade from the 3.2 version of the suite. Here's a pastebin of the error from Apt: http://pastebin.com/3BqZVvCn
After an upgrade, ECW's can't be used, event after installing the extensions into the GeoServer's WEB-INF/lib folder. ECW appears as a format, ECW is listed by GDAL as available, creating an ECW store works, but the store is always empty... Valid stores that worked in 3.2 dont' work on 4.0.
A secondary issue is that some file permissions seem to be broken on upgrading from 3.2 to 4.0, these are exhibited by failure to load some aspects of the GeoServer interface, such as logging.
Does anyone else have these issues, and if so, are there any known work-arounds? It seems to me that a resolution would be for Boundless to add in the missing packages to their repository, but that may be naive.