I've long wanted a home scanner that would scan to local or network storage without intervention. In the 1990s I thought about ways to add such a facility to an existing scanner, but it didn't make business case. About 3-4 years ago scan PDF to network shares appeared in our office machines and my Brother MFC -7820N, and now our office scanners store PDF scans on an internal drive.
It's a fantastic feature, but the 7820N implementation is quirky. It doesn't work well with multi-user machines and it requires an oddball embedded server run on the recipient machine.
The MFC-9440CN was first introduced in 2007 (and is probably about to be replaced, so it's on sale now) and I'm writing about this now. Since this is a feature I'm extremely interested in I think there's a bit of a marketing failure here.
Brother's web site has some additional documentation ...
- Scan to USB
Brother’s Scan to USB enables you to scan documents direct to a USB memory device without the need to start up your PC. This means you can make digitised copies of documents immediately, including handwritten meeting notes, certificates, business cards, and drawings so you can be sure everything has been captured on the USB memory drive for later use.
- Scan to file
Save scanned data into a selected folder for easy information sharing.
- Scan to FTP ...
Both options 1 and 3 are great for us. I could easily setup an FTP server on my OS X machine that would work in a multi-user environment, and of course the USB function is very simple. The Amazon reviews suggests this feature works, though they also point out that the replacement toner cartridges are fantastically expensive and that B&W printing drains the color toner 
I'm going to have to look into these capabilities. The fact that they're not marketed more widely does emphasize what a weird bird I am ...
 Every vendor I know of is guilty of some form of toner scam. It's an instance of irresistible emergent fraud. In the case of my Brother MFC -7820N the cartridge stops working even when it has ample residual toner. You cover up a transparent port to get a few more months of light duty printing. The scams for these color printers are substantially nastier.