You should first make a clear decision as to whether you need a single-page-application (SPA) or if you’d rather take a multi-page approach.
The greatest benefit of Vue is it’s absence of pedigree. It is fresh and has little baggage. It has been learning from the mistakes and successes of React & Angular. The way we see it, Vue is lightweight & easy to learn.
It has got some fairly basic docs but they do a good job, and while there isn’t a great deal to learn compared to angular – this is a good thing as it’s deceptively powerful. PageKit, Python China are two of of the projects using Vue among many. Here’s the list. Also, it has two way data binding facility like Angular and Virtual DOM like React.
Regarding Angular, there is a blog post about versioning and releasing Angular starting with the v2 release. There will be one major update every six months, and there will be a deprecation period of at least six months (two major releases). There are some experimental APIs marked in the documentation with shorter deprecation periods. There is no official announcement yet, but according to this article, the Angular team has announced long-term-support versions starting with Angular 4. Those will be supported for at least one year beyond the next major version release. This means Angular 4 will be supported until at least September 2018 with bug-fixes and important patches. In most cases, updating Angular from v2 to v4 is as easy as updating the Angular dependencies. Angular also offers a guide with information as to whether further changes are needed.
The update process for Vue 1.x to 2.0 should be easy for a small app — the developer team has asserted that 90% of the APIs stayed the same. There is a nice upgrade-diagnostic migration-helper tool working on the console. One developer noted that the update from v1 to v2 was still no fun in a big app. Unfortunately, there is no clear (public) roadmap about the next major version or information on plans for LTS versions.
One more thing: Angular is a full framework and offers a lot of things bundled together. React is more flexible than Angular, and you will probably wind up using more independent, unsettled, fast-moving libraries — this means that you need to take care of the corresponding updates and migrations on your own. It could also be a detriment if certain packages are no longer maintained or some other package becomes the de facto standard at some point.