Yes ESAT 1.30+ will run on a 2008 server. Depending on you security settings you may have to allow all 3 ESAT modules to run. (ESATInformer, ESATAgent and ESATRetriever) they are located in c:\program files\sidebit\esatinformer. In some cases ESATAdmin may need permission too.
ESAT 1.30 needs NET 1.1 installed. There were some reports that Exchange OWA was not working properly if NET 1.1 was installed on the server in 2007. But we have not had any feedback in this regard for some time. We assume that issue was taken care of. by MS
In addition the ESAT webport needs to be open on the firewall. Typically that port is 84 or 5050. The ESATInformer Requesters or the ESATAgent webport keys show the port ESAT is using.
We have a new ESAT 1.41 beta that is based on dot net 4.0 and runs on 32 or 64 bit Os's. You can download it in our download section