The KJV and NIV translations make this appear to be a prophecy but nothing here is in the future tense. The key verbs are subjunctive, meaning that they "might" happen at some time, past, or future. the Greek, this verse does not appear to be a prophecy about the future at all, but a statement about what happens when we die: we see Jesus in his realm. This makes more sense in the context of the previous verse, which is also less of a prophecy than it appears.
In Greek, this seems more like what happens when some of those "having stood" there die. The "standing" is an action completed in the past, not happening now. They see Jesus in his natural realm. In this context, the "having stood here" could mean anyone who has died.
Christ's Words in Matthew as a Guide to 40 Days of Prayer.