Atlassian is trying to own the migration path here, IMO. Trello was never really meant to manage software products, and I've been part of two separate teams that moved from Trello to JIRA when a PM who wanted more enterprise-y management features came on board.
Fog Creek always pitched Trello as a general list app, not a bug tracker, and refused to add features that would've geared it specifically toward bug tracking. I would venture a guess that Fog Creek kind of accidentally shot FogzBugz in the foot with Trello.
My impression is that Atlassian sees Trello's userbase as a strong opportunity to upsell to the enterprise-style tooling in JIRA and recruit more people into the JIRA ecosystem. If this is indeed the value they see, then it wouldn't make sense to change anything about Trello's fundamentals. They'll probably just create a JIRA plugin and plaster JIRA ads all over the place.
Fog Creek always pitched Trello as a general list app, not a bug tracker, and refused to add features that would've geared it specifically toward bug tracking. I would venture a guess that Fog Creek kind of accidentally shot FogzBugz in the foot with Trello.
My impression is that Atlassian sees Trello's userbase as a strong opportunity to upsell to the enterprise-style tooling in JIRA and recruit more people into the JIRA ecosystem. If this is indeed the value they see, then it wouldn't make sense to change anything about Trello's fundamentals. They'll probably just create a JIRA plugin and plaster JIRA ads all over the place.