And, why is there no sign of 5800 support on Nokia maps 3 ?
Probably because Maps 3 is still in beta, and the 5800 is the very first S60 5th Edition device.
Maps 3 should be out on the 5800 by June though, because it's being bundled with the N97.
Also, why can't the user download or update the maps facility, it's not on the nokia maps page?
I'm not sure what you mean by downloading the maps facility, but you can download maps onto your computer using the Nokia Map Loader, then transfer them to your phone, as noted in the article. Here's the download page (scroll to the bottom to see the Map Loader section):
http://europe.nokia.com/A4984199
I think that Nokia maps has degenerated to a novelty item on the 5800, nothing more than a showcase of an "almost but not quite" application.
I'm sorry, but you're talking entirely about problems in navigation and route-planning (which are as Steve noted problems on the server rather than in the application itself). There's a LOT more to Nokia Maps than that, as anyone reading the tutorial will find out.
I don't have a car so I never really use the navigation aspect at all (though I did for the sake of researching the tutorial) but I still use Nokia Maps quite a bit.
Because I'm on foot and on public transport, I don't really need to know the exact route as the bus or train or taxi driver already knows where they're going, and finding the way to walk from one place to another isn't difficult to do on a map. So automated navigation isn't really my top priority.
My main uses for Nokia Maps are:
1) To tell me exactly where I am 😊 Simply showing my location on a detailed map is probably the thing I value the most on Nokia Maps, it stops me getting lost.
2) To find out and show me where I need to get to. For example I recently used it while on a trip to find the nearest pharmacy. That was a really important bit of help because I might have missed my train and been without medicine for the journey, but Maps told me there was a pharmacy just round the corner from the station.
3) To tell other people where I am. Nokia Maps' "send" function sends an exact postal address for your current location, or any other location, even if you don't know the address yourself. That means the recipient doesn't have to have a GPS phone because the address is entirely in the text message, and I know that it will work with all mobile phones. That's also quite nice to know in case I'm in an emergency and have to ask for help.
4) To store my favourite places so I can see where they are on the map. For example, on the same trip I found a really good restaurant and saved it to "My Places", so I can easily go back to it the next time I'm in town.
Obviously problems with postcode lookups aren't acceptable, especially as navigation is a pay-for service, and if it carries on then people should demand some kind of explanation and/or compensation from Nokia (in the UK that would be through trading standards I think). But it's a bit harsh to describe Nokia Maps as a "novelty" because one aspect is having problems.