It would be fantastic to see a glider pilot specific version of SD, especially now that a basic glide range calculation is there anyway. Having the clear airspace display, NOTAMs, etc. would be a major benefit to glider pilots. There are a few glider specific features that would need to be developed to make the product appeal to glider pilots:
- Glider specific task management (custom turn point sectors, assigned area tasks, ....)
- Final glide calculation which pilot configurable polar curve
- Connection to onboard instruments eg. Flarm
- ...

The current market leader is the Naviter Oudie:
http://www.naviter.si/products/oudie.php?Itemid=257

What do you think?