"deprecated" means they'd rather you do it a newer way. Its not an error but a warning. Essentially deprecated means there's a newer and preferred way of doing something. The main reason to quit using the "deprecated" item would be the possibility that in a future upgrade it is no longer just "deprecated" but in fact is obsolete and no longer available.
An example of this is the "nslookup" command that has been around for years. Most UNIX/Windows versions still have only nslookup by default but it is "deprecated" in Linux in favor of the "host" or "dig" commands.
However it will still work fine as seen below from one of my RHEL 3 boxes:
$ nslookup google
Note: nslookup is deprecated and may be removed from future releases.
Consider using the `dig' or `host' programs instead. Run nslookup with
the `-sil[ent]' option to prevent this message from appearing.
Haven't done wireles on Linux but would suggest you research "wext" if it really concerns you. However it isn't urgent until you get to the point that you want to upgrade.