The Nikon ICE stuff is pretty much mandatory for bulk slide scanning, since it helps you avoid the pain of hand-spotting each picture in Photoshop. Instead, you can just do bulk color corrections in something like Picasa -- pretty fast and efficient. We ended up doing everything at 3000dpi (3755x2466 pixels), which is plenty enough to see the film grain, even of good film (and more than plenty enough to figure out that my parents, on their honeymoon, had very little idea how to focus a 50mm prime lens).

My understanding is that the Nikon bulk feeder is finicky and requires regular attention. When you pay somebody else to do it, they've got a trained monkey watching some large number of these feeders to keep the throughput up. You get back DVD-Rs of the images, which you can then process yourself. If you're really feeling the need to get your hands dirty, then I'd recommend saving it for the handful of pictures (from the first pass) that are real keepers. Then you can try to rent yourself some time on a much more expensive scanner (e.g., Rayko, in San Francisco, rents time on a high-end Imacon scanner for $45/hour).