I am a Realtor in JP since 1990. I have been through (although just the end of it) one market decline.
Buyers (& renters) will continue to come to Jamaica Plain. The schools & hospitals (and all of the jobs they provide) are plentiful.
Then the community, the green space and the ease of public transportation will keep our area very strong.
Some of us... agents, sellers & buyers may have to adjust to longer mortgage com. dates, using more experienced mortgage people, Realtors etc.
I am not worried.
Even if markets are local (and they are), the economy is global and a large portion of the buying pool has investments that have just lost value, live in homes that are losing value, and have jobs that are becoming less stable, and will need mortgages that are now more difficult to obtain. Not everyone fits into these categories, but a large portion of the buying pool does and that will impact the market. Sure your home may be a one of kind that is in high demand, and if that is the case, you just need one buyer and you may be fine.
The Greater Boston market has done very well over the past few months, actually recording gains according to the Case-Schiller index, but you things have been rough over the last couple of weeks.
Good luck. Also, some investors like to buy condos that already have tenants in place.
Right now the absorption rate for condo's in JP is 28 properties a month. This means at the moment there are 4 months worth of inventory on the market which is quite strong compared to some other soft markets.
Hope that helps!