This map isn't necessarily brand new, but it is a nice look at the MTA's big East Side Access project, which will connect the LIRR to Grand Central Terminal. amNew York (which has a gallery) and the NY Times visited the tunnel near 63rd Street and 2nd Avenue, where parts for the tunnel boring machine are being delivered. The TBM will then drill through rock to extend an existing tunnel to Grand Central. Fun fact via AMNY: After the TBM eats through stone, the pieces "about the size of 'buffalo chips,' according to one contractor on the site, are pulled out by conveyor belt."
As for the existing tunnel under East 63rd Street, the Times had this look at its past:
For years, the 63rd Street double-decker tunnel started in 1969 has been mocked as the “tunnel to nowhere.” The tunnel’s top level was built for subway trains, but no trains ran there until 1989. But even then service ended after just one stop into Queens, and it was not until 2001 that a connector was built linking the tunnel to the subway lines that run along Queens Boulevard.
Even today, the tunnel’s lower deck still leads nowhere. Built to carry Long Island Rail Road trains to the East Side of Manhattan, the tunnel’s lower portion was never connected to anything, and it has remained a dead-end anomaly, a testament to high aspirations and low finances.
Of course, now the project is up and running, thanks to a chunk of federal money. And the LIRR concourse at Grand Central would be built under the Metro-North one - it'll be pretty modern-looking.