The question you have asked is a tough one to accurately answer due to the constant expansion in this area. Also many people have there own views on where Lake Nona begins and ends. Moss Park Road also gets thrown into this area as well!
This area is a very attractive area because of its location to the airport and the expansion of the medical campus. I have visited many of the communities in this area and I am amazed that even during a down economy the builders are still pushing forward. As of recent I have noticed continued expansion from the restaurants and big box stores.
Best of luck if you have any other questions feel free to contact me!
All the answers so far are actually wrong with respect to Lake Nona's boundaries.
2,000 as the number of housing units is about right.
Got a Lake Nona question? Contact me and I'll get it sorted.
I'm not sure how many people live there.. but maybe this map will help you with location.
The smaller area has around 2,000 homes, the larger area has around 5,000 homes (these are approximate numbers taken from tax records). I hope this helps....best regards!