Task: Summarization
Input (English): I have little doubt that the Blue Icicle will get the job done with a Shure SM-58, or similar "dynamic" microphone.  But its claim that it will convert any "condenser" mic, even one that normally requires XLR connection and phantom power, into a "plug 'n play" USB mic should not be taken at face value.  I say this because I have an acquaintance with the original Audio Technica AT2020 Condenser mic who had intermittent and marginal success when he tried such a conversion.  In the long run, he would have been ahead (in terms of both the conversion and saving a few bucks) by purchasing the AT2020 USB mic.  As it is, the Blue Icicle is probably the best such converter on the market (the comparably priced LightSnake cable will not convert condenser mics, despite what you may have read).  So, if necessary, give it a try--and more than one.  But make sure there are return privileges.
Output (English): Promising--if it works. Not always a guaranteed solution.