Firstly, I'm not in anyway involved with Jolla Mobile. I know some of the people there and I've been hearing about it for a while now. There are seriously talented people involved and I'm sure that they will be able to push real stuff out. I'm really looking forward to see what these people are able to produce.
Based on the information Jolla has published, they are going to continue the work started in MeeGo and are going to utilize Mer -core as basis for their operating system and Qt/QML as UI toolkit. They are also contributing back to the Mer -project. This is an excellent starting point. I think we demonstrated in the Nemo Mobile, that even with a relatively small team you can develop modern phone software using these technologies and existing open source components.
For Jolla it will be vital that they will concentrate their limited resources correctly. The main part of this must be the user interface, since all the other building blocks needed (ofono, bluez, gstreamer, pulseaudio, connman, etc.) were already pretty well stabilized in MeeGo and are now available in either Mer- or in Nemo Mobile and thus can be quite easily utilized in Jolla. I would build the new user interface with QML and I would utilize some of the existing Qt Components implementations as components. One option would be to use Qt Components from Harmattan. Those already exist in Nemo Mobile and can provide quite easy compatibility with QML based Harmattan apps.
Jolla has already gotten quite a lot of press coverage. This is obviously good. There are a lot of people that really want alternatives to currently successful platforms. There is a downside though. Many people are having unrealistically high expectations. People seem to expect that the actual product would be having all the features N9 has with much better HW and then all the annoying bugs fixed and missing features added. I do not think that will happen. I'd expect to see more focused product at first. A product with good HW, great user experience, but fairly limited set of built-in features (for example I would not expect to see MMS in first release). And in time there would be SW updates to bring more features to the platform.
Other problem with high visibility is that people are already talking about Jolla as challenger to iOS, Android, and others. In reality smartphone market is huge and there should be plenty of niches where an agile company can make a good profitable business without having a big global market share. If the expectation level is too high, people would easily deem Jolla as a failure, even if Jolla would find a niche for itself. This may make raising the needed capital investments difficult later on when Jolla would be ready to grow out of the niche.
Ecosystem is a big deal for global mass market mobile operating systems, because the devices need to be able to connect to all the popular services. Easiest way to do that is to allow the service providers to write apps to access the services. Pretty much all the major mobile operating systems integrate to all the most popular services. iOS with its huge developer ecosystem has a big advantage since it is the platform that startups target first.
Initially, there can't be a big ecosystem of software providers around Jolla. However, I do not think this is too bad problem as long as Jolla targets correct market and is able to provide solutions to integrate to the services that are the most relevant in that particular market.
The N900 and the N9 showed a bit different way of integrating to various services on the cloud. Both included a pluggable interface that allows seamless UI integration of 3rd party services for sharing, chat, and contacts. Both included implementations of various popular services (Facebook, Google, Twitter, etc.) out of the box and developers provided plugins that supported additional services. By utilizing similar approach Jolla should be able to integrate the most popular services, and they need to obviously extend the support to any services that are popular on the market they select.
This is not enough to satisfy all, but should be enough for a lot of people. For example on my N9 I only frequently use 3rd party Google Reader -app in addition to the services that come with device. If Jolla comes out with decent support of services and provides interface for community to integrate new ones, like N9 does, that should be enough to satisfy a lot of customers.
One of the most positive thing about Jolla is that it will raise awareness that you do not need to be a huge corporation to build consumer products. Things like Mer -core and QML really make it easier even for small companies to build interesting, connected products with cool user interfaces. Good example of QML's power on low-end hardware is presentation Andrew Baldwin held on Devaamo 2012 -summit.
I really wish all the best for Jolla. While it is not yet clear if Jolla will be success, I do think that it is showing us the future. There will be small companies utilizing open source technologies and ways of working to build cool stuff.