So I was over in London attending a certain cupping event you may have heard about, when I took a wander through John Lewis and what did I find but the very thing we've been discussing for over a month! It's new and called a "Presso". Check out their homepage:
http://www.presso.co.uk/
The diagram on the details section gives a better idea.
Here's what I remember from the instructions:
Heat the water seperatly
Fill the porta filter as normal
Pour the hot water in to the "filling area" up to the mark for one shot or two
Raise the handles and hold for ten seconds as a pre infusion
Then lower the handles trying for a 22 second pull
There's only a two shot filter, so for one shot you'd have to half fill it so I wouldn't expect great singles and the filter itself looks about the same as my Pavoni, 49mm 10-12g. Like all lever machines I'd expect it to be very fussy about grind and tamp.
Check out the
Amazon reviews, real pity there's no review from someone who knows what they're talking about, I doubt Presso "... admitted it could only produce pressure in the 7-8 bar range ..."
I think this could be a great machine for those that want a real espresso but can't afford a real machine, or for camping / travelling. As a lever lover, I'm interested and would love to play with one for a while and see if it really can make great espresso (I can't see why it couldn't), but I'm not going to buy one just to find out if it's worth buying!