I'm using Vista and Outlook 2007 and mine syncs both ways.
The person is probably having Outlook sync issues like everyone else is having. At first, I couldn't sync all my contacts over, until I found this workaround I made up.
Give it more time, and they will fix more bugs.
Once you sync the iPhone with iTunes it goes through all the different sections: music, contacts, and calendar. If you've added some contacts or appointments, it will usually give you a warning message during the sync process that "syncing will change more than 5% of your contacts." Once you do that any changes you had added to your iPhone calendar or contacts, will now be on your Outlook contacts and calendar.
You don't do anything. IF you've got contacts or appointments on your phone that you don't have in your outlook software yet, when you plug up the phone it will automatically load those contacts and appointments to your computer.
There's not a manual option for moving the contacts from the phone to the computer. The only manual option you have is to move contacts from some other file into your outlook program. Once you select the Outlook options on the iTunes contacts page, it should sync both ways: from computer to phone and from phone to computer. It wouldn't be worth much if it didn't. The whole point is to be able to add appointments and contacts when you're away from your computer and then sync them with your desktop when you're back in the office.