I'm slightly concerned that the original poster 'mbd' has rightly pointed out that he has some experience from previous disputes - That almost indicates a "Sailing Close to the wind" approach overall. And to my mind if your going to operate in these areas you need to be a little bit more familiar with TM law in general.
In the first instance I believe the "Attempting unauthorised profit or trading from anothers TM rights" is going to be the prong of attack - If one should materialise.
In the other instances I refer to I wasn't using the domains in the same way I am thinking of using this pending drop, but I know that would have little impact on a dispute.
I know if a dispute arose either with the brand owner personally or through Nominet I would hand it over immediately, which is why I wouldn't throw money at it or a lot of time. I think the brand owner would find it difficult (not to mention a bit of a pr disaster) to try and push for anything else. As I said I'd ONLY promote the product.
I'm reasonably well up on domain trademark law, I had my fair share of experiences back in the day and there's no way I'd go back there, but as it's been mentioned, not everyone who owns a trademark understands what they're entitled to. This brand I'm talking about, there's a chap who's targeted half a dozen of their products' names and he apprears to have had the domains for several years... although they do just resolve to a holding page.
Incidentally, in my experience there's little thanks that comes your way in pointing out to a registrant that their domain is about to expire.
Every corporation is different.
I had a domain which included a brand name in it. They fabricated a story to make out I was tarnishing their brand and they tried to sue me. I ended up handing over the domain to avoid litigation and it closed my business down overnight - my fault, I accept that. What aggravated me though was that my business ONLY sold, and by proxy promoted, their products. After taking it off me they let it go to a 404 and then within a year they let the domain drop... It's available to register now and there are still a handful of banklinks from 10 years ago still active...
So, it all added up to them putting me out of business, which stopped me buying and selling THEIR products. No one gained anything, maybe you could argue they were in control of 0.0000001% of their brand for ten months and they probably spent several grand for the pleasure. Today their brand is struggling and they were way out in front a decade ago... Their competitors who are now market leaders did little in terms of domain chasing, yes they've done some, but they've let 1000s of domains carry on... Why? I think it's simple, they're happier with people keeping their brand in the public eye so long as it doesn't defame it. Free publicity.
In another instance, an acquaintance of mine was doing the exact same process as I was doing except they were working on another brand. When the brand found out, yes they were initially hostile, but they eventually chose to work with the owner even though they could have taken the domain off him no questions asked. Two years later the domain owner was a multi-millionaire and his site became a main sales channel for the brand online. He wasn't even really internet savy, he just negotiated well and once he knew the opportunity was there he set about making himself savy. It was a perfect example of a win / win.
Back to the domain that's dropping soon... IMO, the UK distributor is doing a pretty lame job as far as promoting the brand online and they've had years to sort it. In my view the brand owner could choose either of the two approaches.
Apologies for the long post, just though it might be of interest.