The Engadget article points out some of the flaws with the N900: it’s not a polished product. The user interface isn’t as slick as the iPhone or the Palm Pre (but it is very pretty). The selection of applications is also limited, but being worked on. The Ovi Store for Maemo is buggy at best. There are glimmers of what the device could be with a little more refinement.
The N900 has one of the best implementations and integrations of Skype and regular phone address book. A Skype call looks just like a regular call. (In fact, Skype works over the 3G network on T-Mobile and not just wifi. The current version of the iPhone, until this past week, only allowed Skype calls over wifi.)
The N900 can’t be viewed as just a phone: it is really a mobile computer with phone capabilities. For example, using the OpenVNC application, it’s possible to remotely log in to a desktop computer or server. Like the iPhone, there are applications for writing blog posts, using instant messengers, and accessing most popular social networking sites. Unlike the iPhone, the N900 is unlocked: it can be used on any network and any available application can be installed. (The iPhone can install applications, but only those approved by Apple and made available on the application store.)
I’ve used the N900 for a few months now and have thoroughly enjoyed it. I’d highly recommend it to any of my geeky friends. (It’s so much fun pulling up a Debian console prompt and showing it to unix/linux sys admins. Their eyes light up.)
If you are interested in the N900, see if you can find someone to talk to who has one. Play with it. Read the reviews. If you want something you can use for email, blog posts, and have shell access for complete control over the operating system, the N900 is awesome. If you just want something to make phone calls that has a keyboard and a touch screen, you might be better off with an Android-based phone.