There is basically no difference in monitoring a FAS2020 from monitoring any filer model via snmp.
Pushing and polling snmp is possible. Creating your own user-defined traps is possible. To fire an alarm when let's say used space in a volume reaches 81% - or whatever. Runs like clockwork for me.
There are lots of nagios plugins available as well. NetApp documentation on snmp montoring is very sparsely though. If you are familiar with snmp traps and mibs, you can have a look at /vol/vol0/etc/mibs/traps.dat and /vol/vol0/etc/netapp.mib.
I do not have any experience with integration in OM though
HTH
Peter
