Hey Plugga,
In terms of newer slick options, I've been running Soma Shikoro folding bead tyres in the 700x42 casing for almost 4000km now, and they've been great. Bit heavier than similar Compass tyres, but they do have additional protection that the Compass tyres lack (to favour more supple casings). Just checked on the Australian distributor's website (SCV Imports) and they appear to do a 48c version of the Shikoro now too.
There's definitely a much larger selection of >700x40 tyres available now than when this thread started...although not that many of them are slicks. Maxxis ReFuse is another slick tyre that is now available in 700x40 size, bit heavier/cheaper than the Shikoro. Maxxis Rambler is the next closest to slick that I can think of, easily the quickest and lightest of the knobby tires I've tried, but you'd definitely want the 60tpi (not the 120tpi) version for commuting.