user experience needs to be at the heart of design

You've certainly heard this before. I am sure I am stating the obvious and boring you with common sense statements. However, it appears it is not that common sense. Let me explain: for the last three years I've worked for a user centered design consultancy and quite often clients would come to us at the final stages of their design asking for and seeking some user centred approach to their beleaguered projects. We would do our best and in some cases do  exceedingly well in redirecting focus and helping deliver a final product designed around the user needs. However, I've always been frustrated with being involved at the later stages of a project rather than being there at its infancy where I could make more significant contributions and help save time and money + deliver a user centred product. I was convinced that the only way, or rather, the most obvious way is to work directly for the client, be part of their team, so I can influence the project from its early day. So, I updated my CV and got a job at one of the best digital agencies around. Well if there is anywhere I can influence direction it will be here where all big builds come to exist.
Wrong? I honestly do not know yet, but I somehow have the feeling that I will face the same struggles as an insider as I did as an outsider. I still have t look for a few answer: where does the power lies? is it the creatives, technologists or UEs that lead? If it is not the UEs, how can I then upset the staus quo? how can I make sure they all know that leaving the user on the sidelines amounts to designing and delivering projects purely for own indulgence, some sort of creative masturbation?
Well we'll see....