I came to this thread wanting @ mentions, but I just sat down to write out how I would want them to work, and one of the big issues I see is that with the existing [[...]] syntax, the scope is clear, so one can have spaces in names. With @... syntax, you have to split on whitespace – so while I can currently reference [[Barry van Oudtshoorn]], or alias [[New South Wales Government|NSW Gov]], I don’t know how I could do that with @-mentions.
Perhaps @-mentions could work a bit like embeds? So a syntax more like this:
The big difference would be allowing one-word references to omit the square brackets – although I would be equally happy if it were simply possible to do a scoped page search when entering @, and have Obsidian auto-expand that to @[[...]]. (Edit: which is what I see @AlanG gets 90% of the way towards earlier in this thread…)