According to hothbricks, the following sets will get the 15% discount during the May the 4th promotion :
7965 Millennium Falcon
10188 Death Star
10221 Super Star Destroyer
10225 R2-D2
10240 Red Five X-Wing Starfighter
75000 Clone Troopers vs. Droidekas
75002 AT-RT
75003 A.Wing Starfighter
75004 Z-95 Headhunter
75021 Republic Gunship
The site claims that this may not be the full list yet.
The soon-to-be retired SSD and R2 are part of the list and that's a very good thing for me
Also keep in mind that this list is for the French S@H, but I would be surprised if it varies much from one region to another.
Edit : it seems you still get VIP points for the discounted item. A 100 set discounted to 85 will give you 85 points.