Paul Winalski wrote:How long has ß been officially deprecated?
Paul, the ß has not been deprecated. They've just aligned its usage with that of the other consonants. Again, the basic rule is that a single consonant indicates that the preceding vowel is long, whereas a double consonant indicates that the preceding vowel is short. (There are still exceptions and a few other rules which don't need to be discussed here.)
ß, (scharfes s), is considered a single consonant and ss is its doubled counterpart. In the old orthography ß still showed up as an exception to be memorized preceding short vowels, e.g. muß which now must be written muss. The same goes for daß/dass, floß/floss etc. If, however, you can't type an ß, then ss is OK, but that's the way it's always been just like adding an e after a, o, u if you can't type an umlaut.
These and other long debated changes were introduced in '04, taught in schools since August '06 as optional, and then in August '07 became binding. There are tweaks for other German-speaking countries outside the FRG.
The whole thing is laid out here: Deutsche Rechtschreibung, if you want to plough through it. And there are quite a few other places on the web where the changes are catalogued and explained. Just type in deutsche Rechtschreibung.
So, just keep on using that good old ß, just use it in the right places.