HI.
I just got my printer scanning on the network. It works from both my iMac and MacBook (wirelessly) and here's how:
1. GO to HP's website: www.hp.com and click on "Support and Drivers" at the top
2. Click on "Drivers and Software" on the next page
3. Search for the M1522 (I have a M1522nf) and click on the printer that you want
4. THIS IS KEY: When the list of OS comes up choose "Mac OS X" WITH NO VERSION EXTENSION - that is don't go to "Mac OS X 10.7"
5. Download and install the most recent version of hte driver. I ended up with:
HPLaserJetM152MFPseries1.4.0.dmg
6. Run the program and install the software.
You do not need to plug the USB cable into the printer if it is a networked printer.
7. You can then scan from "HP Director" - the program you've installed.
Image Capture doesn't work, you need to use the HP software, but so far that works well for me. I've done it on both my Macs.