Not having much luck in sourcing camber adjustment for my 250. Looks like TJ Motorsports are planning to do something (see link) but unfortunately it's the TJ Motorsports in the USA and not the one in Watford http://my.is/forums/f180/is250-350-test-ca...kit-thm-374677/

Eibach appear to have camber adjusters of the ES 250/300, so have asked them if they could be suitable for the IS250 or if not, did they have any plans to design a set.

Here's the ones for the ES. They're available in pairs, either 15mm and 17mm:Car fitment
Lexus: ES250, ES300,
The new EZ Cam™ XR is designed for non-slotted struts. It allows both positive and negative camber changes up to approximately 1.75 degree (depending on vehicle) by replacing the upper O.E. strut/spindle bolt. This easy to use adjuster provides built-in adjustment over the life of a vehicle just by rotating the head of the bolt. Each kit contains two cam bolt assemblies, enough for both sides of the vehicle. MasterPaks of 10 are available. Use wrench #85825 to adjust.

NO Special Tools
NO Grinding Necessary

Click to view attachmentClick to view attachment

The EZ adjusters are no good since you have a single "off hub" anchor point.... Did you speak to Prolex?

Is there a problem with the IS250 cambers like the old IS200?

reason i ask is the IS250 is probably the next car i'll own...

No, not as sold other than some tram-lining issues

Yes, spoke to Dave but he doesn't know of any that are currently available, although thought perhaps that Eiback may be working on it. Looks like the best bet at the moment is TJ Motorsports in the States. Not a surprise really as there's probably still only a handful that have been lowered in the UK, and as you know mine is on the American Eibach springs that give a lower drop at the front than the European spec, so perhaps mine is the only one that has the problem in the UK.
Loads of demand in the States as indicated from the number of enquiries from 'Club Lexus' and 'My IS' so TJ Motorsports have some incentive to develop the adjusters.