lingscars.com is one of the few that actually gives prices rather than asking you to contact them for a quote. What they're doing as specials will probably apply to most other brokers too.
Not sure the scrappage scheme would be compatible with leasing as the point of it is that you don't own the car, you just rent it for a fixed term. Could probably be used as the deposit for a PCP-type deal though (guaranteed final value set, you either pay it at the end or hand back).
Leasing can work well in some circumstances – for people who want a new car, definately want to change it after 2 or 3 years (as there's no option to keep it), know their needs and mileage won't change, and aren't that fussed about what they have – as the best deals are on models that have excess stock.
It can work out quite well for ex-company car drivers, as long as your mileage isn't too high (most are quoted for 10k/year, it gets quite a bit pricier with more) and of course your job is secure – as if you got made redundant, the car and it's payments are your problem, not the company's.
Equally it can work out badly for some people – a couple I know leased a small family hatchback which worked out fine for them and their one child. Then she got pregnant with twins and they found out just how punitive the early termination clauses are on these leases – unlike an owned but financed deal, they couldn't pay it off and sell/trade in, they ended up keeping it for the term but getting another bigger car. A colleague got screwed by excess mileage after his wife picked a new house that was 40 miles rather than 3 from the office.
Personally I'm not that fussed about brand new so bought at 6 months old and even if I financed it, it would work out quite a bit cheaper than leasing a new one for the 25k miles a year. Plus I can go on running it for 4 or 5 years rather than being compelled to hand it back after 3, and I just pocket the difference between my car allowance and what it actually costs to run.