TL:DR
As outlined in the new whitelisting process, this is a proposal to increase the UNI capFactor from cap1 to cap2 ($1M -> $3M).
The Proposal
This is a proposal to increase the UNI cap tier from cap1 to cap2. UNI currently has >$1.8M in adjusted liquidity and has surpassed its $1M cap essentially since its inception.
Uniswap is one of the oldest and most respected projects on Ethereum; this may make it deserving of a higher cap tier on Balancer.
What is UNI?
UNI is the governance token of Uniswap, it currently has a >$600M market cap. The uniswap platform currently transacts more volume than any other decentralized exchange.