Yes, inner joins like that are still valid because they are still unambiguous and thus 100% logically valid. Equi-joins function exactly the same using WHERE joins rather than a JOIN clause. Old-style outer joins can have ambiguities, which is why the were unequivocally removed.
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial: "If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them."