There is a lot of planned growth and development still going on in the Issaquah Highlands. For local home owners it will be a mixed blessing. Many people have been attracted to the area for the easy commuting and walkability. As the Theaters and new shops appear the streets will be busier and there could me more evening traffic and noise, depending on how close you are to everything.
If this appeals to you, I would say as long as you know what to expect, you should be fine. If the added activity is not something you would enjoy, find a quieter spot, there are many available in the area.