With most firmware revisions there are also incremental updates. The incremental updates are usually to patch jailbreaks and other security flaws or to fix a small bug(5.0.1 is an incremental update). The in-between builds like 5.1(upcoming) usually add something more than that. In this case, it is supposed to finally fix any lingering iPhone4S battery drain issues it also adds changes to iCloud features, accounts and a few other things. The reason it would be smart for pod2g to wait is because 5.1 is already in beta 2, and if this firmware follows the same pattern as previous firmwares there will be one more beta and then a public release(likely within the first few weeks of January). So far the exploit pod2g is using has not been patched and if it remains unpatched in 5.1 it would be better to wait to reveal to Apple how the jailbreak works so that iPhone4S users and all iDevice users can be up to date.
