I understand your concern for outgoing against new model. But here is my stance on that if that is what is holding you back.
You already know what you need, does the current one satisfy that need?
Second, to share my actual experience. When we were planning to purchase a subcompact back in 2008, I was recommending between a Getz or City. We of course leaned towards the City. That being said, the actual time frame we were picking out the car was about 1 month to 2 months max from when the model will be launched.
Naturally, my family was contemplating whether to wait for the new model or not. I quickly answered them with a simple phrase, I don't need a new model. I need this specific car model (1.3S AT). Plus, the price difference was already known by then. The 1.3 S AT back then was 660k, the new model of the same trim would be 760k, a whopping 100k (15%) price increase.
I never regretted my decision back then and was really happy.
Then my uncle asked about our City. He was planning to buy the new 1.3S AT. This was the new 1.3 Vtec one, we had the 1.3i-DSi engine. Naturally I let him drive the "weaker" 1.3 City and he liked it and bought the new City.
After 3 years of ownership, he sold it as it felt lacking in power. Keep in mind that during this time, I think up to now, there are no test drives for walkin clients. I also drove his car quite a few time and it does.
So new doesn't really mean better for me. It depends on the situation.
If you plan to own the vehicle long term, depreciation really plays too little a part in that and it is something we always do in our family. Our vehicles last more than 10 years, excluding 1 car which was flooded and impossible to repair on a budget. We sell them only when it becomes too much of a hassle to maintain them.