Using these parameters, the late 90s and early 00s were well above trend, whereas last year's highs only just peeped above the upper line and the current value is hovering a little above the centre of the hi-lo wedge.
The implications are that the next low, if it comes soon, shouldn't be worse than around 4,500, and by 2010 (when I'm guessing the tide will turn) the bracket would be in the 4,700 - 7,000 bracket, with a midpoint of c. 5,850.
Taking the market at close yesterday and extrapolating to that 5,850 midpoint, would imply a future return (ignoring dividends) over the next 16 months, of c. 2.5% p.a. - not nearly as good as cash, especially in an ISA. On the same assumptions, to achieve an ex-dividend return of 6% p.a. would require entry into the market at c. 5,400.
On this tentative line of reasoning, we should be looking for a re-entry opportunity somewhere in the 4,500 - 5,400 level, say 5,000. Shall we wait for the next shoe to drop?