There is nothing bad about doing this, the SD RSN's have always been CONUS. What has happened the past couple of years was if you had a package like NBA-LP and a game was produced in HD you couldn't see it unless D* put it on ch 94/95 or you were in the HD beam for that home team RSN. Now with the RSN's going CONUS you'll be able to see that game in HD anywhere if you subscribe to the correct sports subscription.
Example, you have NBA-LP and live in Las Vegas and want to watch a Chicago Bulls game played in Chicago. Comcast Sports Net Chicago produces the game in HD and was on the CSN Chicago HD spotbeam, you wouldn't be able to see it in Las Vegas. With the RSN move to CONUS you'd now be able to see the came since CSN Chicago would now be on the CONUS .
plus, i'm not sure but i would think you might see other hd broadcasts....like college football and/or basketball being broadcast on an rsn.