What I will write next ... you decide?

At my frequent bookstore appearances, one of the most frequent questions I get (right behind the hypochondria-inducing ``have you written them all yet? You;re not going to die before you finish the series are you?'') is: What are you writing next?
Now while I have begun writing on the train again (let's face it, my only other alternative is listening to someone gibbering away on their mobile) I am still undecided as to which way to go.
Basically I have four stories I would dearly love to tell, two trilogies and two stand-alone novels.
I should say that it may well not be my final decision as to which way I go ... obviously a massive amount depends on sales for my existing trilogy and how that affects whether or not HarperCollins wants to keep me on, as well as what they might be interested in.
Naturally I would like the opportunity to write them all!
But I am curious to know what people think, what they would like to see. I'd love to hear opinions as to what you might like to read - and who knows, it could be the thing that tips me towards one over another!
So, in no particular order these are:
Trilogy 1: Set 10 years after the events of Radiant Child, many new challenges await the surviving characters from The Dragon Sword Histories. I can't say too much more than this, for fear of giving away parts of The Radiant Child, but they will all be tested to the limits - and beyond...
Trilogy 2: One of the great fantasy cliches is elves and magic. But what if one elf failed his test of magic? Well, he would be exiled to the brutal human world, driven out of all he has known. But, with his knowledge, his skills and his archery, he might just be a wild card in a people's fight for freedom from a ruthless King. with no singing, no dancing and definitely no elven poetry (he breaks up an inn when the drinkers mock him) he teams up with a young bard with dreams of peace and a young dancer with dreams of magic to change not just the human world but the hidden elven one as well.
Stand-alone 1: Loosely (very loosely) based on the Japanese tale of The 47 Ronin (Google it if you are interested). But this is in a fantasy setting and focuses less on Japanese tradition and more on a story of a sword captain whose Lord might be the saviour of an empire - if he survives. He must find out how far you are prepared to go for honour, for revenge - and whether you are prepared to lose yourself, your family, everything, to save your country. With Keanu Reeves reportedly signed up for a film adaptation of the Japanese legend, slated for a 2012 release, this might be the only window I have to write this tale...
Stand-alone 2: The term ``hero'' gets applied to sportsmen too easily. And in a country where the national sport is a cross between rugby and gladiatorial combat, the champion team is given everything they want. But when they travel overseas on an exhibition tour, they find they are being used by an evil King to distract his people. Forced out of their privileged existence, caught up in a rebellion, this team must decide if they want to be real heroes, even if it costs them their lives...
So please, tell me what interests you - even rank them in order if you have the time/desire!