Simulink was the major reason for choosing Matlab for a current project. Hope this move by Wolfram also results in improves for Simulink or in a lower price. It currently sells for around 6k.
Matlab+Simulink had no competing alternative until this.
This is simply a different view to model systems such as can be done in Simulink. Simulink has a (differential) equation-centric view whereas Modelica (of which SystemModeller is an implementation using the mathematical capabilities of Mathematica) has more an object-oriented view where external interfaces are exposed and connected and the behaviour as expressed by the differential equations is hidden. Modelica is a standardized language, see e.g. http://openmodelica.org for an open source implementation.
It is simply not true that there wasn't a Simulink alternative until now. Modelica exists since 1997 (cf. http://en.wikipedia.org/wiki/Modelica) and there are several commercial implementations of it: Dymola, MapleSim, MathModelica (which now in v3 has been purchased by Wolfram and has been rebranded as SystemModeller), CATIA Sytems and probably some more.
Adaption of Modelica has been slow since engineers are more exposed to Matlab/Simulink during their education and this base is slow to change. Considering license, training and experience costs this is certainly understandable. However, I know that several German car makers are gradually changing over to Modelica since the models are easier to understand for new people joining the projects (and to escape the vendor lock-in of Simulink).
Thanks, but I'm aware of Modelica and Scilab. In fact I have used them even more than Matlab, which I have only been using for about a month.
All the academic, hobbist and professional communities in what I'm doing use Matlab heavily and specifically. Available code/modules/"toolboxes" and support are severely lacking in Scilab and Modelica. I wish I had the time and the knowledge to contribute back but I currently don't.
