You should not mix up the the bib file-format and bibtex. Bibtex is a program that sorts and formats entries of the bib-file according to a style you specify.
Bibtex has a few disadvantages, especially now when more and more people use utf8 as a file encoding.
The problem of using a bib file with bibtex was always that you had to chose a style (
\bibliographystyle) which is rather difficult to customise.
Biblatex is now a novel way of managing the look of your ciations in the text and the entries in the bibliography. As a backend (for sorting and such things) it can use either bibtex or biber. Biber is certeinly the future as it supports utf8, improved crossref's and more.
Biblatex still uses a bib file as database, so this is not outdated.
Now when you start from scratch, it is advisible to use biblatex because it is so easy to customise as it uses latex-macros. Your database can still be a bib file and you can use a tool such as jabref, mendeley, zotero or ... to maintain it