I actually don’t think this is such a big deal. I’ve heard of Orthodox being baptised by sprinkling – for instance, one small infant who was sprinkled because it was so cold one Romanian winter that they could barely prevent the font from freezing over! It’s just that we still hold to the original norm, whereas Roman Catholicism seems to have changed the economic exception into the norm.
Ideally everyone should be baptised by triple immersion where possible, but sprinkling would not make a baptism invalid (although we don’t accept any heterodox baptisms as valid in and of themselves). I myself was sprinkled as an infant in an Anglican church but brought up Lutheran (weird Protestant ecclesiology) but was accepted into the Orthodox Church by Chrismation alone, which is only done if the original baptism was [i:hcdcyf0y]valid in form[/i:hcdcyf0y]. It is easy to make too much out of this issue.