Exciting stuff at the CloudMade launch the other day in Holborn. CloudMade are a commercial entity set up by OpenStreetMap founder Steve Coast and Nick Black which, judging from those in attendance at the launch, has about 20 employees - many OpenStreetMap people from the UK and a few managerial/corporate Americans running the business side of things.
The main selling points of CloudMade's mapping APIs, which provide a commercially-reliable map tile service on top of the OpenStreetMap data, are a) the OpenStreetMap data, which has richness of detail not found in other map tiles - particularly in pedestrian elements like footpaths, though motorway junctions are well represented too; b) liberal licensing, with no constraints on uses of the map tiles (unlike NavTeq and Tele Atlas, which don't allow competitors to use their maps for real-time navigation) and c) editable styles for the map tiles, which update immediately (smart caching and early regeneration of images in map hot spots reduce the impact of this on CloudMade's servers).
All this puts CloudMade squarely in competition with Google's mapping APIs - and Google will have a hard time keeping up. While Google's maps are excellent for driving, they have little detail at the pedestrian level, so far. It makes sense for Google to use one consistent, distinctive style for their road map, reducing the cognitive load of understanding maps on different sites, but I think being able to customise colour schemes for different uses, to emphasise certain features, could be very useful.
The cost of running CloudMade's services is intended to be covered by location-specific advertising, the revenue from which will be shared with users of the map APIs ("you don't pay us - we pay you!", the success of which will obviously depend on how much advertising revenue is available to be shared).
There's a routing API, which as far as I know is the first time driving instructions have been automatically generated based on user-contributed mapping data, leading to the inevitable future news story where people are surreptitiously taking their own streets off the map so that traffic won't get routed down it... Of course, this would be unlikely to go unnoticed in OpenStreetMap, but you might get away with marking a couple of extra speed bumps :-)
There's an iPhone API, which is similar to PhoneGap: allowing websites to make use of the phone's location data. The Javascript APIs react to user interaction and handle mapping using essentially the same methods as Google Maps, making it easy to switch between the two.
There's also a FireEagle-like API for posting your location. Nothing yet for attaching notes to a location, as far as I know, which would be a useful addition.
There's not much detailed altitude information in OpenStreetMap so far - apparently there is radar data accurate to 300m2, but not yet the level of information that would be useful in OpenCycleMap within cities (it seems that altitude measurement in handheld GPS devices isn't very accurate).
When I tried CloudMade's API a few months ago I ended up back with Google as a few details were still missing, but I believe those have all been added in now so I'm looking forward to giving it another try.