Ideas for a simple, but somewhat extendable computer bus

I've always thought STD-Bus missed a real opportunity here. Small enough to be cost effective (relative to the size of, say, S-100 (bonus, no stupid power supply issues)), sane, flexible enough bus structure that I believe there are at least CPU cards using: - 4004/4040 (pre-standard?) - 8080/8085/Z-80 and the myriad of variants - 8088/8086/80188/10186 through at least 80486, including variants and second sources - 8048/8051 and the vast numbers of variants - 8096/8097 and variants - 6800 and variants - 68HC11 and variants - 6809/6309 - 6502 and variants - 68xxx and variants up to at least the 68040 and 68332 - TMS9900/9995 - RCA 1802 - Signetics 2650 - Novix Forth More importantly, the vast number of compatible I/O cards that were produced. Much alternative history to be pondered. KJ