The first one is Personal Information Manager (PIM) plugin written by Mladen Pejaković. This plugin basically mimics Opera's ability to autofill forms with your stored personal information. If you enable this plugin and save eg. your name in it, you will see on webpages yellow-bordered inputs. These inputs can be auto-filled with PIM as simply as pressing Ctrl+Enter.
|Personal Information Manager's settings dialog|
|Facebook register form can now be autofilled with Ctrl+Enter|
GreaseMonkey in QupZilla supports installing userscripts with clicking Install button on userscripts.org site (that means, if you click on any link that ends with user.js, you will be asked if you want to install it to GreaseMonkey).
There are, unfortunately, some restrictions due to QtWebKit engine. Userscripts cannot make cross-origin XMLHttpRequest (eg. they can only make same-origin request). Also some GM_ functions does not work, mainly script resources and persistent settings. Those functions are present as empty functions (they do nothing), so at least they won't interrupt script execution.
But besides of this, everything should work as expected.
These new plugins will be part of upcoming 1.3.0 release that is going to be released very soon. I hope it won't take longer than 2-3 days.