It will also be good for the restaurants at the Swan and Dolphin.It doesn't directly impact those resorts with a direct stop. It would be easy to walk over to the EPCOT station and take a ride back to DHS but it probably wouldn't be a whole lot faster than the boats. I think earlier the estimate was about 15 mins from EPCOT to DHS on the gondola. I think the friendship boats take about 25 mins to a half hour park to park since they stop and dock at each resort on their way. If you are staying at Swan/Dolphin it's much faster to get to/from DHS since it's the last stop going and the first stop coming home. For BW it should be slightly faster to walk to IG and ride the gondolas and avoid stopping at the other 2 resorts, especially if you have to wait for the boat to arrive.
The gondolas will also provide direct transportation to the Boardwalk itself (via a short walk from IG) for about 7,000 rooms full of guests. It should help business at the restaurants and might make the Boardwalk a little more relevant as an entertainment location.