There was something magical about this number 35 for centuries. Until Tendulkar surpassed this number, till about six years ago, no batsman had scored more than total 35 international hundreds - test and ODI put together. Some batsmen had balanced number of hundreds (e.g. Haynes 18 and 17) whereas some had predominantly test hundreds (34 and 1 for Gavaskar) which could be because the fewer number of ODIs they played and the lack of importance to those at that time. In fact Gavaskar just fell 4 short of that mark in his last test innings. But nobody had the total beyond 35. Tendulkar was the first one to go beyond 35 total international hundreds. Now he is the first one likely to reach and go beyond 35 test hundreds.
In addition to the 35th century, Tendulkar may also reach 10,000 test runs. He just needs another 121 for that. He still has Lara beyond him but is likely to surpass him at least in this series. The other three ahead of him are Steve Waugh, Gavaskar and Border.
It would be interesting to see whether any other batting record is broken during this series. No Indian batsman has ever scored more than 100 runs in a session. With Sehwag opening, that doesn't look all that unlikely.
The series aggregate records between India-Pak are less likely to be broken since those were from five and six test series earlier. Most of those are in excess of 500 for Indians and more than 700 for Pakistanis.
Tendulkar has also never scored a century in both the innings of a test. It will be wonderful to see that broken too. The last time an Indian has done that was when Dravid did it in New Zealand in 1999. Gavaskar has done it three times - once each in India, Pakistan and West Indies. Vijay Hazare did it once too.
In general, Indian batting has really had a tremendous time in the last 2-3 years. Many of the big batting records have been accomplished in this duration. (Also, 8 of India's 21 away test wins are also in this approximate duration). For 18 years Gavaskar's 236* was the highest Indian score and it was even less before that. In last four years, that has been surpassed five times (Laxman 281* at Calcutta, Tendulkar 241* at Sydney, Sehwag 309 at Multan, Dravid 270 at Rawalpindi and Tendulkar 248* at Dhaka). I hope there is another one around the corner. In all there have been five by Dravid, four by Tendulkar and one each by Laxman and Sehwag. Double-centuries were so rare in the nineties that since Gavaskar's retirement, the only ones were by Manjrekar at Lahore in '89, Shastri at Sydney in '92, Kambli in '93 against England and Zimbabwe each and Sidhu at Port of Spain in '97, and most of these were laborious match-saving knocks. All the recent ones have been in a dominating position and except the miss at Sydeny, have resulted in an Indian win. Even the near-misses have been fabulous - Dravid 180 at Calcutta, Tendulkar 193 at Leeds in 2002, Tendulkar 194* at Multan and Sehwag 195 at Melbourne last year.
India has had 11 scores of 600 or more - 6 of those have come in last five years and 4 of thoes outside India. In fact if Dravid had waited for 25 more runs (and 6 more for Tendulkar) in Multan, India would have become the only team to score back to back 700+ runs! Of course, that certainly wasn't more important than the win we achieved there.