On your specific case though... I honestly like the sound of your job now... It seems as though there isn't to much job security where you are now...

But it's almost impossible to say what the situation might be at the new place as well... At some of the companies i've been at, many many times over they have hired for positions that were mundane in 4 months and the person was left without a position. Other times people have taken a position genuinally thinking it was right for them, and then realising the security was great until the realised their boss was a complete asshole, and being out of work for 2 months would actually be less stressful than having to work at such a place...

It's a hard choice with jobs, and I think a whole lot of where you end up is luck. And whether a place is really right for you is luck as well..

If I was you, it sounds like you are happy where you are...
- I would make sure that you have a resume and all your documents up to date incase you are put out of work and you are immediately ready to apply for new positions.... If you are really commited and work just as hard at getting a job as you would IN a job, you can get one pretty fast.
- Get some really great references written from your employer and collegue's that you work with at the moment..
- Try to organise some spare money into a savings that will hold you at bare minimum until you get another job..

Basically you may not be able to control what happens with your job position right now, but as far as 'security' goes, try to do some of the above things and have yourself 100% prepared for possibly being out of work and looking for something new,,, and in a way, that is a type of security that might make you feel better about your current situation...

Biggest thing,,,, Make the most of what you have when you have it.... You've got a great position at the moment, and you know that it might not be for ever,,,, so don't waste money and really work at making the most of every cent you get while it is still coming easily for you..