I've been to this place twice in the last few weeks and have been very happy with this addition to Wilmington's (somewhat lame) Asian food scene. I'm always a little wary of "pan-Asian" menus, and Rasa Sayang has Malay, Thai, and Singaporean dishes. But the heart of the kitchen is Malay, so I've stuck with this part of the menu. The lunch choices are a little sparse, but the menu gets bigger at dinner, so I'd recommend going in the evening. I'd also like to request of the owners that they put noodle soups on the dinner menu, not just lunch!
Food-wise, I've had the roti canai (twice--for whatever reason the pancake was better at dinner, but good both times), the kang kung belacan (stir-fried Malay greens with shrimp paste, excellent although portion way too big for a pile of greens!), and the curry chicken noodle soup (not as good as some laksa I've had in the past, but tasty). Mr. travelmad478 had the Malay stir-fried noodles (with shrimp and squid--can't recall the name of the dish)--that one was a bit on the bland side, in my opinion. I like spicy :-)
The location across from Astra Zeneca on 202 seems very well chosen--the lunch service is clearly getting a lot of business from AZ's East and South Asian work force. I also went last night for dinner, on a Wednesday, and they were doing a decent amount of business then too.
Definitely, this one is worth adding to the rotation. I'd like to try the rest of the Malay dishes, particularly at dinner when there seem to be many more choices--there's nowhere else in the area to get Malay food. Prices are very reasonable (cheaper than Jasmine) and portions generous--our waiter last night actually advised us to order more sparingly for that reason. We split one starter and two entrees and still ended up taking home half the plate of greens.