Learning German is useful on many levels, it will make it easier to get through everyday life (though Germans in general will speak English quite well official stuff tends to be in German only), it will also allow you better access to the German market.
Could you point me to the programs for entrepreneurs? I run a meetup for international entrepreneurs in Germany and that question comes a lot.
http://www.bamf.de/EN/Infothek/FragenAntworten/BlaueKarteEU/...
The thing is that it doesn't cover people wanting to come here to found their own startups.
Also if I understand it correctly the "high skilled" part means having a degree in Germany, that's why I mentioned the "have an Engineering degree" in my other comment.
would love to get more experiences from others, all my friends that used the blue card were for Engineer jobs and they had degrees.
Learning German will differentiate you if you don' have one of those.