As an IT professional, the skills you use for your job are your most valuable asset - most gainful employment within the sector relies on some specialist knowledge. Whether from experience or education, the things you have learned define the job you can do.
It is safe to say that any investment in your skills is worthwhile, then - expanding your knowledge of things IT related will help greatly in developing your career - cementing and diversifying your current role (with greater chances for advancement) and improving your prospects for later roles as well.The dangers of over-specialisation
The detriments of a narrow skill set are all too obvious, then - technology is a fast moving sector to work in, so if you don't keep your skills up to date you could get stuck in a legacy support dead end, or worse - find yourself replaced with a new wave of fresh faced developers toting the latest buzzwords and paradigms.
That's not to say that a certain degree of focus can't be a bad thing - if you're amongst the few real experts in a niche area, you can certainly make a very tidy profit - but all the same it is wise to be sensitive to the evolving landscape of IT. If you're in a receding area of expertise, over-specialising can be dangerous.
Certain subcultures in tech can breed this kind of lack of adaptability - those in the almost self-contained Java and .NET worlds are more vulnerable than most. Being involved in a close community is largely a good thing, at least as far as support is concerned - but it's not hard to become isolated from other areas and miss out on some of the more up-and-coming languages, platforms and techniques.Being a 'jack-of-all-trades' isn't much better
Keeping an open mind to new technologies can pay dividends - but it's wise to be at least slightly cautious. Overzealous chasing of the bleeding edge can lead to a lack of depth to your knowledge - which will adversely affect your skill set as a whole.
Challenge yourself. Expend at least some time broadening your knowledge into adjacent sectors. But never forget the core skills that define your role today - use them as a base, not something disposable to discard at the first sign of change in an industry.
While the life of a technology worker can be fast paced, the changes that come about are evolutionary - and with the right mindset, and with a little effort expended to keep your awareness fresh, you can do well.