I'm sorry, but this is plainly obvious. Now there are a lot of useful comments in this thread about IT ageism and all that, but the wording of the submission is plain as day to anyone who cares to read between the lines: For continuing in IT you mention no particular positives, and harp on the negative aspect of having to stay up to date and 're-invent yourself'. Whereas w.r.t. management you only say that you seriously enjoy doing it and are seriously considering spending the rest of your working life on it.
Ermmmm....
Granted, you then go on to imply that management is for senile old men, but this only serves to clarify to your audience why you're having this issue: you have deep-seated preconceptions as to what type of people actually go into management, and while you respect the work itself and would like to shine in that respect, you can't get past your own mental blocks of seeing them all as Dilbert-styled PHBs.
Well, by the power vested in me by Slashdot, I officially set you free. Go forth and manage, AND stay up to date on tech, and be the good manager that will render Dilbert obsolete. Use all the grey matter you have - and frankly you will need to - to properly challenge your talented techie workers while using them to the best of their abilities and making the latter obvious to those above you.
I wish you all the best in your management career. Remember, while it's not the same as tech work, don't be afraid to treat it the same when it comes to research - there are innumerable useful books written to help ease you into management coming from any techie standpoint.
How many weeks are there in a light year?