I had actually planned to do GB/GBC linking (because I want to trade Pokemon with myself :p) but I got sidetracked with GBA emulation. One of the stated project goals is to get that link functionality working once GBE is integrated into GBE+. At some point, GBA-to-GBA linking is something I want to emulate as well. VBAM seems capable of doing it, but it's never worked for me on Linux, and no$GBA is closed-source, so I have a lot of incentive to see this feature added.
As for emulating DS-to-DS wifi, I would love to tackle that, but currently that's terra incognita. No one's done that for commercial games, even no$GBA. But that's something of a pipedream for me. Imagine, Mario Kart DS in HD with 4 of your buddies online *drools*. It's certainly possible, but it's a big challenge since not everything the DS does with WiFi is documented (even for "local" multiplayer that doesn't involved Nintendo's network). A lot a stuff needs to be reverse engineered. But like I said, I'm interested in emulation as a challenge
As for emulating DS-to-DS wifi, I would love to tackle that, but currently that's terra incognita. No one's done that for commercial games, even no$GBA. But that's something of a pipedream for me. Imagine, Mario Kart DS in HD with 4 of your buddies online *drools*. It's certainly possible, but it's a big challenge since not everything the DS does with WiFi is documented (even for "local" multiplayer that doesn't involved Nintendo's network). A lot a stuff needs to be reverse engineered. But like I said, I'm interested in emulation as a challenge