No, you're right. FW800 hard drive enclosures are available, but not popular. Basically that's about the range of FW800 devices. Again, there are a few other products, but they're not selling too well. FW800 is a little ahead of its time for anything that's not a high-speed hard drive. Peripherals today have a hard time filling up FW400, iPod included.
Despite attempts, Firewire never achieved any sort of market penetration. Not because it wasn't good at what it did, but because it was complicated as a protocol and expensive as hardware. It's not so expensive anymore, but it's still complicated. USB had several years of development going for it, and a relatively natural extension from existing serial communications and from PCI, an already entrenched standard. USB had a speed limit, though, that was considered sufficient when it was developed but later proved to be inadequate when external hard drives and big file-size DV cameras took off. Firewire was there to meet that emerging market, but USB 2.0 popped up on the scene later.
It has many advantages over Firewire, but one key disadvantage: Firewire was designed for large file transfers and sustained speed, where USB 2.0 simple allowed for greater speed. But USB already had a huge market of peripherals, was backwards compatible, and used a proven and popular communications protocol. USB 2.0 wasn't a risky move like FW, so more manufacturers were willing to jump on board to cement its dominance. The Firewire people went back to the drawing boards to give FW a clear advantage and came up with FW800. It's great and very impressive, but almost nothing takes advantage of its faster speed, and its lack of backwards-compatible connectors mean it will probably never make it in the portable world (where USB ports are backwards compatible, FW800 requires a separate connector, taking up valuable space).