My observation is that this ups the ante for an acquisition of NavTeq by a major player. Google and NavTeq already have a close relationship, and buying NavTeq would give Google ownership of a major information source as well as intellectual property. Microsoft would be interested as a defense against Google as well as expansion for their own mapping and navigation business. Garmin can't be happy about the prospect of NavTeq going to a competitor and so could bid on their own or with partners.
As for NavTeq itself, it will be competing not only with companies that are farther up the food chain (Google, Microsoft) and aggressively expanding their services in ways that could eat into NavTeq's core business (directly and/or indirectly), but now they have a motivated, well-funded, and integrated competitor in TomTom that could alter the landscape and have unknown consequences.
In fact, I believe it was the spectre of Google, Microsoft, etc., that made an acquisition by TomTom seem like the better long-term alternative for TeleAtlas than the risk of increasing marginalization and possible irrelevance.