It's no secret that the next iPhone will support LTE, but the Wall Street Journal is reporting this evening that it'll work on LTE networks "around the world" in the US, Europe, and Asia. That's significant because it could allow owners to roam on LTE across multiple countries; to date, LTE band diversity and hardware limitations have mostly limited LTE handsets to single markets or regions.
The chipsets certainly exist now to enable multi-market LTE: the international version of the Nokia Lumia 920, just announced this week, supports a staggering five bands of LTE in a single model, for instance. The concept of universal LTE, unfortunately, is a bit far off — dozens of bands are in play globally, and WSJ notes that the new iPhone isn't likely to support service on every carrier that currently has LTE deployed. The odds-on favorites would include AT&T and Verizon in the US, but Sprint's unique deployment would be a tougher one to convince Apple to support (for what it's worth, the carrier's CFO noted in March that it could eventually carry an LTE-enabled model). In Europe, several markets have LTE commercially deployed including Germany, while Orange / T-Mobile joint venture Everything Everywhere is widely expected to announce it in the coming weeks in the UK.
The iPhone 5 is all but guaranteed to be announced at next week's Apple event; we'll be there live.