Well I will be the odd one out and say go for it.
I started on the 800, upgraded to the 925 and then back in September or so I upgraded to the 930.
The comment about it being "quite old" isn't very accurate as it's not even a year old yet. It's the last high end that came out.
For me, I can see myself using this phone for another two years at least and it will handle anything Windows 10 can dish out compared to any current Lumias currently available..... Note that the 1520 has been discontinued by MS.
If you can wait for a new flagship with all the bells and whistles and can afford it, by all means.... But if you can't and your 800 is really showing its age like mine does, the 930 is a great option.
The only advantage the 925 has over the 930 is that it has Glance and that it takes slight better low light shots from my testing of both.... Though only slight. You will love the screen, the camera and the guts it has.
As a minor thing, I also noticed that my 930 isn't as slippery in the hands as compared to the 925. After the second day of owning my 925, it slipped out of my hand and onto my kitchen tiles and landing face down after a bounce. The screen was fine but unresponsive and the back plastic popped off from the frame on the corner where a dent in the frame existed. I got it back together and after about three hours I got it to run like normal again.
Haven't had that problem with the 930. It just kind of fits in the hand right.
I don't know about others but it's the best Lumia I have used so far.
I do understand where you are coming from about worrying about getting this phone and a new one coming out soon after.
When I went on contract with my 800, the 810 came out a month later.
When my contract was up, I got the 925 but before I did, I asked my carrier multiple times when the 930 was coming out but they didn't know. As my 800 was having screen issues when I made or received calls, I couldn't wait much longer so I got the 925. A month and a half later the 930 was released in Australia. I eventually bought an unlocked 930 and my 925 is a backup.
Though I also have a backup 625 & 630 testing W10.
My wife has a 1320 and my coworker has a 1020. Out of all of these devices, the 930 still tops them all.
As far as I am concerned, the 930 won't be showing its age for another 1-2 years. Hell it still out specs the iPhone 6 and if you check the specs online, your 925 is about par with the iPhone 6 in most categories..... The 930 will remain relevant for a while still.
The battery is also better than the 925.... By a little bit of course.
And then there's "Hey Cortana"
There are many in the WC community who swear by their 920's and that it's still a great phone today to the point where they don't consider upgrading to the 925, 928, 930 or the 1520.
I never really understood this until now as I kind of feel the same way about my 930.
Great Display and Resolution
Plenty of RAM
32GB storage is plenty for me
4K Video with 5.1 Surround Sound
Hey Cortana makes up for no Glance and only the 930 & 1520 have this very handy feature
The Next Flagship will need to have some spectacular specs to make me even consider upgrading my 930 at this point.
And a 0.4 or 0.5 extra MP in the camera isn't going to do it.
I can wait for biometric unlocking
An extra gig of RAM isn't needed at this point over my current 2GB.
Storage space is enough right now.
Put Windows 10 on my 930 and I'll be happy for a long time to come.