I did a lot of work on the i860 back in the early 90's - boards, a kernel, and so on. This was at a time when a 40 or 50MHz processor was state-of-the-art. At the time, my view was that it was the first thing that Intel had got right since DRAM, and the 8080 and 8085. The 386 architecture was a disaster, and it only survived thanks to Microsoft.
The 860 wasn't a general-purpose processor, though - it was all about high-speed floating point, and you had to hand-write your assembler to get the most out of it. It was essentially targeted as a co-processor. It had almost zero competition - the DEC Alpha went nowhere, and Fujitsu's uVP never took off. They also cost me £1000 a shot in the early days, which didn't help. It was, incidentally, "VLIW", because of all the extra bits required to specify how to wire up the FPUs and datapaths.
I don't think it ever really died, though. I'm pretty sure a lot of the technology ended up in the Pentium. I think it was probably seen internally in Intel as a testbed for the Pentium, but I haven't seen this confirmed anywhere.