An entity can be interested (legally) in the outcome of a lawsuit, or it may simply be interested (in the go-sports-team-from-my-hometown-or-university! sense) in the outcome. Under a recent Business Court ruling, only the former supports intervention under Rule 24.
Time Warner Entertainment Advance / Newhouse Partnership v. Town of Landis involved access to utility poles, a type of dispute committed to the Business Court under 2009 legislation. The North Carolina Association of Electric Cooperatives ("NCAEC"), an organization of 26 electric membership corporations across North Carolina, sought leave to intervene under Rule 24 as a 
defendant aligned with the Town. NCAEC admitted that it had no direct interest in the outcome of the dispute between the plaintiff and the defendant, but was concerned about the potential precedential effect of a ruling that would establish a methodology for use in future cases.
The Court denied NCAEC’s request to intervene. First, NCAEC could not intervene as of right because it had neither a statutory right to intervene nor an interest relating to the specific property or transaction (i.e. the particular utility poles at issue). "Instead, NCAEC has at best a general interest in the precedent that may be set in this case regarding the methodology for calculating pole attachment rates, terms, and conditions, which the Court concludes is insufficient to allow intervention as of right pursuant to Rule 24."
NCAEC could not intervene permissibly either. Rule 24(b)(2) requires a common question of fact or law for permissive intervention, and the Court held that NCAEC had not put forth any claim for relief for any ripe dispute. According to Judge Diaz, allowing intervention would force the Court to issue an advisory opinion in advance of any actual dispute between NCAEC and any cable provider. Moreover, allowing intervention and the addition of new counterclaims would threaten the statutory mandate that utility access disputes be resolved by the Court within 180 days of commencement.
The Court permitted NCAEC an opportunity to be heard, however. To the extent that future proceedings in the case involved the question of the rate methodology to be applied by the Court, the Court allowed NCAEC leave to appear as amicus curiae on that one issue.