In general, this is why I strongly believe most of transhumanism will come in the form of wearable tech for the near future. People accept adding an iPad to their items in their bag. They accept a phone sitting in their pocket, easily reachable at all times. Such things are cheap, can be upgraded rapidly, are lightweight enough to carry everywhere and become ubiquitous. We already wear a great deal of clothing, giving an amazing possible space for technological enhancement of our bodies while still retaining the cheap and easily upgradable and disposable nature we value in our technology. Thus, in the near term, this is where to watch for really cool transhumanism tech. Even with the previous example of smartphones/tablets. Millions of people now carry with them everywhere devices which allow for instant communication with anyone anywhere on the planet, as well as instant access to much of the world's store in information via the internet, while also providing a means of entertainment. Without so much as noticing, the entire world gained wizard-like powers. And this will only get better.
In contrast, I feel the surgical aspect of transhumanism is currently very overplayed. Sure, it's coming, but, in general, it also isn't coming to augment us. Surgical implantation of macro-scale devices is:
1. extremely costly
2. extremely invasive
3. dangerous
4. you need to do it all over again for a simple firmware upgrade, requiring both more cost and causing a continually increasing amount of tissue damage
Which is why, in general, it is only done when an organ fails that you either can not live without (artificial heart) or you can not live anything close to a normal life without (artificial limb). Additionally, there is very little benefit to implantation. It complicates device design to an incredible degree, due to concerns about temperature, size, ect. Basic brain data can be acquired with external sensors, with signal loss partially corrected by decent pattern recognition AI (which is why systems like the Emotiv headset has a learning period). There is only one major purpose which cannot be replicated through wearable tech: direct nervous system connection. So between all those issues, there is an immense barrier-to-entry for any sort of body-mod augmentation becoming mainstream.... For the time being.
Now here's what it will take, and what will allow it to take off in the future:
Miniaturization. Implantable augmentation tech only becomes of net benefit when it is small and non-disruptive enough to be done on an outpatient basis. An injection like you would get a shot, taken in pill form, or similar. This requires miniaturization; but of a degree which we will almost certainly see. This will result in a dramatic shift from the current major barriers to enhancement tech. Again, the major benefit of implantation, which cannot be acquired otherwise, is direct neural feedback. I suspect it would, for the most part, come earlier than most implantation tech, as we already see some signs of it in the articles I linked; particularly the artificial eye, and is already an advanced field of research. Compare that to other implantable tech, and you see a rather big divide between 'direct neural interface,' and 'magnets inserted under the skin' in terms of research and development funds and effort. I also suspect that, eventually, it may well come in the form of a more unified interface, rather that being specific to a single device/application. A sort of IO kit which wirelessly transmits to an external device (similar to other mature implantable devices, like pacemakers).
Implantable tech outside of this or medically-required devices faces a rather large hurdle. It may well overcome it, but I sincerely doubt it will overcome it on a large scale; for reasons ranging ffrom psychological to tradition and socio-economic conditions.