As i understand, this can work for me as well, if i do the following?
1. Downloading NetPrinterPrefs v1.15 from Aminet (this could be ported to PPC for AmigaOS4, as it is 68k based) and install it in SYS:Prefs
2. Run NetPrinterPrefs and set up my Canon Pixma MP620 to run wirelessly, by giving the wireless IP address of my AirLink AC5000 router
3. Using "netprinter.device" and giving the right unit from the printer, if i understand correctly, and ensure everything runs correctly
4. Printing out a test from AmigaOS 4.1 Update 6 and see if everything was successful
I suppose these are what i should do, is that correct? Just need to know. I'm giving it a test this weekend, so hopefully it should be a success. Fingers crossed

UPDATE: While NetPrinter is very handy, i could not find any driver for Canon Pixma MP620 to use, not even wirelessy. The Linux and Mac version of TurboPrint, which are more modern, both have drivers for just about all printers of today, including the Canon Pixma MP620. Unfortunately, the old Amiga version of TurboPrint doesn't.
Theoretically, it should be possible to port the Linux version of TurboPrint to Amiga or either work on a completely new printer support for AmigaOS4, that also uses the NetPrinter in some way by locating the "netprinter.device" from SYS:DEVS. This should be possible. The question is rather HOW can all this be done?
For now, i have no choice but to forget about this printer until a solution is in place.