The method call you stated simply creates a java profile object from the given directory of profile information which is then passed to Firefox via the WebDriver instance.
In order to get Firefox to persist your driver and make it available from profile manager, you need to edit the file profiles.ini, on my (Windows 7) machine this was in:
%APPDATA%\Roaming\Mozilla\Firefox
The Profiles directory within this folder contains the stores of existing Firefox profiles, which are quite handy to copy when you want to use an existing profile as the template for a new one.
Your mileage may vary depending on your OS, but I'm sure you can find it with a quick search. Using your example, you'd then add the following to this file (where N in the header is the next unused profile number):
[ProfileN]
Name=selenium
IsRelative=0
Path=D:\Selenium
This will cause Firefox Profile Manager to load the profile and will allow you to then launch Firefox manually with this profile to configure or test it, which is what I presume you want to do.
Once you have created a named profile in this way, you can assign it to your driver in Selenium like this:
ProfilesIni allProfiles = new ProfilesIni();
FirefoxProfile profile = allProfiles.getProfile("selenium");
WebDriver driver = FirefoxDriver(profile);
Where "selenium" is the same as the Name property in the profiles.ini file.