We worry that after the 454 shutdown, Newbler will no longer be available, meaning that large swathes of the current scientific literature that relied for their analysis on the newbler software can no longer be recapitulated from the raw data. Also, long after the 454 shutdown, many researchers will have to process their 454 sequencing data, and many may still want to rely on Newbler for that purpose.
Additionally, Newbler represents a very valuable contribution to the field of genome assembly and mapping. Software developers can learn from the algorithms and implementations of the Newbler code, opening up for reusing these in other programs. Also, there is the hope that developers will improve upon the program, for example by adding support for other sequencing technologies, or assembling with longer reads.
For more information, see these blog posts: http://flxlexblog.wordpress.com/2014/01/31/make-newbler-open-sourcehttp://flxlexblog.wordpress.com/2014/02/10/make-newbler-open-source-an-update/