Actually, the 1.0 and 1.1 builds of Snowdrop are not compatible with JBAS6, because of an internal change (migration from VFS2 to VFS3). Compatibility with JBAS6 is the goal of Snowdrop 2.
1) If you are using Spring 3, then you can run your application as-is (i.e. without the VFS application contexts), but make sure that you use 3.0.3 or later because of https://jira.springframework.org/browse/SPR-7197
2) For the Spring deployer, there is a JBAS 6 version which is also Spring 3.0 based, that can be found here for now [1]. A release for this is forthcoming, before JBAS 6 CR1 comes out.
This works with JBAS 6.0.0-M3, but there shouldn't be any issue with it running against a later version of JBAS. Please let me know if this doesn't work.
https://repository.jboss.org/nexus/content/groups/public-jboss/org/jboss/snowdrop/jboss-spring-deployer/2.0.0-M1-SP1/jboss-spring-deployer-2.0.0-M1-SP1.zip
Hope this helps,
Marius