tl/dr: I both like the idea of including this file but have reservations.  Also, it doesn't work for me.

I believe the way you are supposed to use this file is by right clicking on it and selecting "Run As"->"ElasticSearch".  I like the idea because it runs with more normal configuration.  Probably should add -ea because you'll be testing with this.  I wonder if there is some way to get M2Eclipse to just pick this up.

Unfortunately this file isn't working for me.  It complains about missing project_loc.  Maybe I'm using an old version or something:
Version: Kepler Release
Build id: 20130614-0229

I've had trouble in the past with files like this only working with certain versions of Eclipse that start out as the modern version but quickly become outdated.  It might be better to just have nice instructions on how to run Elasticsearch embedded in Eclipse on the how to contribute page or something.