Advice on updating technology

Hey Guys,

So my technology hardware is extremely outdated (Think BB9900, Dell inspirion, and no tablet), and this tech-buying season I'm looking to upgrade my phone/tablet/pc. I thought I had all the answers but now am re-evaluating and was hoping for some advice.

I originally wanted the Yoga 2 Pro, Note 3, and the (hopefully) to be released nexus 10 2013.

The reason I am currently questioning this decision, is because I recently had a look at the Dell Venue 11, and I love the fact that a tablet will have a fully functional operating system. (Also, the fully tricked out version might be a great laptop/tablet hybrid)

After that happened, I came across the Lumia 1520 reviews, and realized that WP8 is quickly catching up to Android/iOS, and if they finally merge the OS, it will have a lot of added functionality. However, current day Windows tablets/phones are early in their development compared to Android, so I'm a little less comfortable investing 100% into it.

tl;dr: So after all that preamble, my question comes down to, are these legitimate concerns, and if so, should I delay my purchases to see how the W8.1 tablet world shakes out?

Thanks a lot guys.