What's different? If you connect the app to Evernote, it will now suggest notebook titles based on your location and events that you have on your calendar. The Evernote blog shows an example of a "design meetup" notebook that was created based on a calendar event. You can still change the suggested notebook titles by tapping and typing. The notebooks also now show the location and date when you last added or changed content as well, which provides helpful context about each notebook. The access to your iPad's calendar and location information is used only for the notebook-titling feature.
Version 4.1 of Penultimate also adds new sync options, including the ability to pause sync when you're traveling or working offline and an option to sync only when you're on a WiFi network. If you share your iPad with other family members or co-workers, you can also sign out of the app now.
Evernote Premium subscribers also get some additional goodies, like unlimited access to paper designs in the Paper Shop (these are in-app purchases for those who aren't Premium users) and enhanced security (there's a passcode lock). Premium users also get the ability to create more and larger notebooks, faster access to support and quicker processing of handwritten notes for searching.