I can see why they are doing it but I'll really miss FTP support. A lot of public data continuous to be distributed through FTPs and for a long time Firefox has been the easiest way to browse them.
Agreed, I was on a public FTP site about a month ago browsing through old support files. Now I'll have to configure a client for it.
Edit: this might be a small opportunity for some of the native FTP apps to jump in and handle the links. Click an FTP link in the browser and launch my FTP client with the details passed through.