Yes, you could store the points and give your PC the 1-2 point evolution, and then change them out when you gain a level, just as you can change the delegation of the other evolution pool points.

I'm not too good with formatting so someone else is welcome to reformat this...

>### Aspect
>
> At 10th level, a summoner can **divert up to 2 points** from his eidolon’s evolution pool to add evolutions to himself. ... **The summoner can change the evolutions he receives from these points any time he can change the eidolon’s evolutions.**

<!-- break -->

> ### Evolution Pool  
> <sup>*(from Eidolon abilities)*</sup>
>
> ... Whenever the summoner gains a level, the number in this pool increases and the summoner can spend these points to change the abilities of the eidolon. **These choices are not set. The summoner can change them whenever he gains a level.**

The way I've read those is that every time the summoner gains a level in Summoner, he/she effectively resets the evolutions, gains the full pool of evolution points, then spends them as desired. With the *Aspect* ability, you are diverting points from that pool at any point you could change the eidolon's evolutions.

Thus, when you gain a level and want to store points, you divert the two from the evolution pool. The next time you gain a level, you choose whether you'd like to divert 0, 1, or 2 points with that ability again.